Document:

<PAGE>   1
                                                                     EXHIBIT 4.3

                               AMENDMENT NO. 2 TO

                        PREFERRED SHARES RIGHTS AGREEMENT

        Amendment No. 2 (the "AMENDMENT"), dated as of June 28, 2001, to the
Preferred Shares Rights Agreement (the "RIGHTS AGREEMENT"), dated as of April
22, 1997 and amended as of July 23, 1999, between Cardiac Pathways Corporation,
a Delaware corporation (the "COMPANY"), and Wells Fargo Bank Minnesota, N.A. (as
successor in interest to Norwest Bank Minnesota, N.A.) under the Rights
Agreement, is being executed at the direction of the Company.

        WHEREAS, the Company, Boston Scientific Corporation, a Delaware
corporation ("PARENT"), and Adam Acquisition 2001 Inc., a Delaware corporation
and wholly owned subsidiary of Parent ("MERGER SUB"), intend to enter into an
Agreement and Plan of Merger pursuant to which, among other things, Merger Sub
will commence a tender offer to purchase each outstanding share of common stock
of the Company for $5.267 per share, and thereafter Merger Sub will merge with
the Company and each remaining share of common stock of the Company will be
converted into the right to receive shares of common stock of Parent, upon the
terms and subject to the conditions of the Merger Agreement;

        WHEREAS, on June 28, 2001, the Board of Directors of the Company
resolved to amend the Rights Agreement to render the Rights inapplicable to the
Offer, the Merger and the other transactions contemplated by the Merger
Agreement (as defined below); and

        WHEREAS, Section 27 of the Rights Agreement permits the Company from
time to time to supplement and amend the Rights Agreement.

        NOW, THEREFORE, in consideration of the foregoing and the agreements,
provisions and covenants herein contained, the parties agree as follows:

        1.     Section 1(q) of the Rights Agreement is hereby amended to read in
its entirety as follows:

        "EXPIRATION DATE" shall mean the earliest to occur of: (i) the Close of
Business on the Final Expiration Date, (ii) the Redemption Date, (iii) the time
at which the Board of Directors orders the exchange of the Rights as provided in
Section 24 hereof, or (iv) upon the Effective Time (as such term in defined in
the Agreement and Plan of Merger, dated as of June 28, 2001, including any
amendment or supplement thereto (the "MERGER AGREEMENT") by and among Company,
Boston Scientific, a Delaware corporation ("PARENT"), and Adam Acquisition 2001
Inc., a Delaware corporation and wholly owned subsidiary of Parent).

        2.     Section 1 of the Rights Agreement is hereby amended by adding the
following new paragraph at the end of Section 1:

        "Notwithstanding anything in this Agreement that might otherwise be
deemed to the contrary, neither Parent nor any of its Affiliates or Associates
shall be deemed an Acquiring Person and none of the Distribution Date, Shares
Acquisition Date, Section 13 Event or Triggering Event shall be deemed to occur,
in each such case, by the approval, execution, delivery or performance of

<PAGE>   2
the Merger Agreement among Parent, Adam Acquisition 2001 Inc., a wholly owned
subsidiary of Parent and the Company, the announcement, commencement or
consummation of the Offer or the Merger (each as defined in the Merger
Agreement) or the consummation of the other transactions specifically
contemplated by the Merger Agreement, including the approval, execution,
delivery or performance of the Stockholder Agreements (as defined in the Merger
Agreement), dated as of June 28, 2001 between Parent and certain stockholders of
the Company. No such event shall entitle or permit the holders of the Rights to
exercise the Rights or otherwise affect the rights of the holders of Rights,
including giving the holders of the Rights the right to acquire securities of
any party to the Merger Agreement."

        5.     The Rights Agreement shall not otherwise be supplemented or
amended by virtue of this Amendment, but shall remain in full force and effect.
This Amendment may be executed in one or more counterparts, all of which shall
be considered one and the same amendment and each of which shall be deemed an
original.

        6.     This Amendment No. 2 shall be deemed a contract made under the
laws of the State of Delaware and for all purposes shall be governed by and
construed in accordance with the laws of such State applicable to contracts to
be made and performed entirely within such State.

                           [SIGNATURE PAGE TO FOLLOW]

                                       2
<PAGE>   3

        IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be
duly executed and attested, all as of the day and year first above written.

CARDIAC PATHWAYS CORPORATION                    WELLS FARGO BANK MINNESOTA, N.A.
                                                as Rights Agent

By:   /s/ Thomas M. Prescott                    By:   /s/ Katherine Johnson
    ----------------------------------------       -----------------------------

Name:  Thomas M. Prescott                       Name:  Katherine Johnson
Title: President and Chief Executive Officer    Title: Assistant Vice President<PAGE>   1
                                                                   EXHIBIT 10.23

                                  OFFICE LEASE

                           IRVINE OAKS EXECUTIVE PARK

                      IRVINE OAKS REALTY HOLDING CO., INC.,

                             a Delaware corporation,

                                  as Landlord,

                                       and

                             GADZOOX NETWORKS, INC.,

                             a Delaware corporation,

                                   as Tenant.

                                       -i-
<PAGE>   2

                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                                      PAGE
                                                                                      ----
<S>                                                                                   <C>
ARTICLE 1   PREMISES, BUILDING, PROJECT, AND COMMON AREAS ......................       5
ARTICLE 2   INITIAL LEASE TERM; OPTION TERM ....................................       6
ARTICLE 3   BASE RENT ..........................................................       8
ARTICLE 4   ADDITIONAL RENT ....................................................       9
ARTICLE 5   USE OF PREMISES ....................................................      16
ARTICLE 6   SERVICES AND UTILITIES .............................................      17
ARTICLE 7   REPAIRS ............................................................      19
ARTICLE 8   ADDITIONS AND ALTERATIONS ..........................................      19
ARTICLE 9   COVENANT AGAINST LIENS .............................................      21
ARTICLE 10  INSURANCE ..........................................................      22
ARTICLE 11  DAMAGE AND DESTRUCTION .............................................      25
ARTICLE 12  NONWAIVER ..........................................................      27
ARTICLE 13  CONDEMNATION .......................................................      27
ARTICLE 14  ASSIGNMENT AND SUBLETTING ..........................................      28
ARTICLE 15  SURRENDER OF PREMISES; OWNERSHIP AND REMOVAL OF TRADE FIXTURES .....      32
ARTICLE 16  HOLDING OVER .......................................................      33
ARTICLE 17  ESTOPPEL CERTIFICATES ..............................................      33
ARTICLE 18  SUBORDINATION ......................................................      34
ARTICLE 19  DEFAULTS; REMEDIES .................................................      35
ARTICLE 20  COVENANT OF QUIET ENJOYMENT ........................................      38
ARTICLE 21  SECURITY DEPOSIT ...................................................      38
ARTICLE 22  INTENTIONALLY DELETED ..............................................      38
ARTICLE 23  SIGNS ..............................................................      38
ARTICLE 24  COMPLIANCE WITH LAW ................................................      39
ARTICLE 25  LATE CHARGES .......................................................      39
ARTICLE 26  LANDLORD'S RIGHT TO CURE DEFAULT; PAYMENTS BY TENANT ...............      40
ARTICLE 27  ENTRY BY LANDLORD ..................................................      40
ARTICLE 28  TENANT PARKING .....................................................      41
ARTICLE 29  MISCELLANEOUS PROVISIONS ...........................................      41
</TABLE>

                                      -ii-
<PAGE>   3

EXHIBITS

     A     OUTLINE OF PREMISES

     B     TENANT WORK LETTER

     C     FORM OF NOTICE OF LEASE TERM DATES

     D     RULES AND REGULATIONS

     E     FORM OF TENANT'S ESTOPPEL CERTIFICATE

     F     JANITORIAL SERVICE STANDARDS

<PAGE>   4

                           IRVINE OAKS EXECUTIVE PARK

                          INDEX OF MAJOR DEFINED TERMS

<TABLE>
<CAPTION>
                                                                           LOCATION OF
                                                                         DEFINITION IN
DEFINED TERMS                                                             OFFICE LEASE
-------------                                                             ------------
<S>                                                                      <C>
ABATEMENT EVENT ........................................................      37
ADDITIONAL RENT ........................................................       9
ADDITIONAL TENANT IMPROVEMENT ALLOWANCE ................................       1
ALTERATIONS ............................................................      20
APPROVED WORKING DRAWINGS ..............................................       3
ARCHITECT ..............................................................       2
BASE BUILDING ..........................................................      20
BASE RENT ..............................................................       9
BROKERS ................................................................      45
BUILDING ...............................................................       5
BUILDING COMMON AREAS ..................................................       6
BUILDING DIRECT EXPENSES ...............................................       9
BUILDING OPERATING EXPENSES ............................................      10
BUILDING STRUCTURES ....................................................      19
BUILDING SYSTEMS .......................................................      19
BUILDING TAX EXPENSES ..................................................      10
CODE ...................................................................       1
COMMON AREAS ...........................................................       6
CONTRACTOR .............................................................       3
COST POOLS .............................................................      14
COST PROPOSAL ..........................................................       4
COST PROPOSAL DELIVERY DATE ............................................       4
DIRECT EXPENSES ........................................................      10
EARLY OCCUPANCY PERIOD .................................................       9
ELIGIBILITY PERIOD .....................................................      37
ENGINEERS ..............................................................       2
ESTIMATE ...............................................................      15
ESTIMATE STATEMENT .....................................................      15
ESTIMATED PAYMENT ......................................................      15
EXPENSE PAYMENT ........................................................      14
EXPENSE YEAR ...........................................................      10
FINAL SPACE PLAN .......................................................       3
FINAL WORKING DRAWINGS .................................................       3
FORCE MAJEURE ..........................................................      44
HAZARDOUS MATERIAL .....................................................      11
IRVINE OAKS EXECUTIVE PARK .............................................       5
</TABLE>

<PAGE>   5

<TABLE>
<S>                                                                      <C>
LANDLORD ...............................................................       1
LANDLORD PARTIES .......................................................      22
LANDLORD SUPERVISION FEE ...............................................       2
LANDLORD WORK ..........................................................       6
LEASE ..................................................................       1
LEASE COMMENCEMENT DATE ................................................       6
LEASE EXPIRATION DATE ..................................................       6
LEASE TERM .............................................................       6
LEASE YEAR .............................................................       6
MAIL ...................................................................      44
MORTGAGEES .............................................................      34
NON-STRUCTURAL ALTERATIONS .............................................      19
NOTICES ................................................................      44
OPERATING EXPENSES .....................................................      10
OPTION RENT ............................................................       7
OPTION RENT NOTICE .....................................................       7
OPTION TERM ............................................................       7
ORIGINAL IMPROVEMENTS ..................................................      24
ORIGINAL TENANT ........................................................       7
OTHER IMPROVEMENTS .....................................................      46
OUTSIDE AGREEMENT DATE .................................................       7
OVER-ALLOWANCE AMOUNT ..................................................       4
PERMITS ................................................................       3
PREMISES ...............................................................       5
PROJECT ................................................................       5
PROJECT COMMON AREAS ...................................................       6
PROJECT DIRECT EXPENSES ................................................       9
PROPOSITION 13 .........................................................      13
READY FOR OCCUPANCY ....................................................       5
RENOVATIONS ............................................................      47
RENT ...................................................................       9
RENTABLE SQUARE FEET ...................................................       6
REPAIR PERIOD NOTICE ...................................................      25
SECURITY DEPOSIT .......................................................      38
SPECIFICATIONS .........................................................       2
STANDARD IMPROVEMENT PACKAGE ...........................................       2
STATEMENT ..............................................................      15
SUBJECT SPACE ..........................................................      28
SUMMARY ................................................................       1
TAX EXPENSES ...........................................................      12
TENANT .................................................................       1
TENANT IMPROVEMENT ALLOWANCE ...........................................       1
TENANT IMPROVEMENTS ....................................................       1
TENANT PARTIES .........................................................      22
</TABLE>

                                      -2-
<PAGE>   6

<TABLE>
<S>                                                                      <C>
TENANT WORK LETTER .....................................................       5
TENANT'S BUILDING SHARE ................................................      14
TENANT'S PROJECT SHARE .................................................      14
TENANT'S SUBLEASING COSTS ..............................................      30
TIME DEADLINES .........................................................       3
TRANSFER ...............................................................      30
TRANSFER NOTICE ........................................................      28
TRANSFER PREMIUM .......................................................      30
TRANSFEREE .............................................................      28
TRANSFERS ..............................................................      28
</TABLE>

                                      -3-
<PAGE>   7

                           IRVINE OAKS EXECUTIVE PARK

                                  OFFICE LEASE

         This Office Lease (the "LEASE"), dated as of the date set forth in
Section 1 of the Summary of Basic Lease Information (the "SUMMARY"), below, is
made by and between IRVINE OAKS REALTY HOLDING CO., INC., a Delaware corporation
("LANDLORD"), and GADZOOX NETWORKS, INC., a Delaware corporation ("TENANT").

                       SUMMARY OF BASIC LEASE INFORMATION

<TABLE>
<CAPTION>
  TERMS OF LEASE                                 DESCRIPTION
  --------------                                 -----------
<S>  <C>                           <C>
1.   Date                          October __, 1999

2.   Premises
     (Article 1).

     2.1   Building                That certain building located at 16241 Laguna
                                   Canyon Road, Irvine, California.

     2.2   Premises                13,916 rentable square feet of space (subject
                                   to adjustment as set forth in Section 1.2 of
                                   this Lease) comprising Suite 100 on the first
                                   (1st) floor of the Building, as further set
                                   forth in EXHIBIT A to the Office Lease.

     2.3   Project:                Irvine Oaks Executive Park
                                   16241 - 16277 Laguna Canyon Road
                                   Irvine, California 92718

3.   Lease Term
     (Article 2).

     3.1   Length of Term:         Five (5) years and one (1) month.

     3.2   Lease Commencement      The earlier to occur of (i) the date upon
           Date:                   which Tenant first commences to conduct business
                                   in the Premises and (ii) the date upon which
                                   the Premises are "Ready for Occupancy," as that
                                   term is defined in the Tenant Work Letter,
                                   which date is anticipated to be November 1, 1999.
</TABLE>

<PAGE>   8

<TABLE>
<S>  <C>                           <C>
     3.3   Lease Expiration        The date which is five (5) years and one (1)
           Date:                   month after the Lease Commencement Date.

     3.4   Option Term(s):         One (1) option to extend the Lease Term for a
                                   period of three (3) years, subject to the terms
                                   and conditions of Section 2.2 of the Lease.

4.   Base Rent (Article 3):        (Subject to adjustment as set forth in Section
                                   1.2 of the Lease).
</TABLE>

<TABLE>
<CAPTION>
                                                                           APPROXIMATE
                                                                         MONTHLY RENTAL
                                                                            RATE PER
                                             MONTHLY INSTALLMENT            RENTABLE
 LEASE YEAR         ANNUAL BASE RENT            OF BASE RENT               SQUARE FOOT
 ----------         ----------------         -------------------         --------------
<S>                 <C>                      <C>                         <C>
   *1-12              $263,847.36                $21,987.28                   $1.58
   13-24              $272,196.96                $22,683.08                   $1.63
   28-36              $280,546.56                $23,378.88                   $1.68
   37-48              $288,896.16                $24,074.68                   $1.73
   49-61              $297,245.76                $24,770.48                   $1.78
</TABLE>

    (*Note: Tenant shall not be required to pay any Base Rent attributable to
the first (1st) month of the Lease Term.)

<TABLE>
<S>  <C>                           <C>
5.   Tenant's Share
     (Article 4):

     5.1   Tenant's Building       Approximately 33.24% of the total 41,862 rentable
           Share:                  square feet of the Building.

     5.2   Tenant's Project        Approximately 4.37% of the total 318,663 rentable
           Share:                  square feet of the Project.  (Subject to adjustment as
                                   set forth in Section 1.2 of the Lease).

6.   Permitted Use                 General office use, and software design, testing, and
     (Article 5):                  distribution consistent with a first-class office park.

7.   Security Deposit              $31,728.48.
     (Article 21):

8.   Parking                       Four (4) parking spaces per 1,000 rentable square
     (Article 28):                 feet of the Premises.

</TABLE>

                                      -2-
<PAGE>   9

<TABLE>
<S>  <C>                           <C>
9.   Address of Tenant             5850 Hellyer Avenue
     (Section 29.18):              San Jose, California 95138
                                   Attention:  Ms. Christine Munson
                                               Mr. Wayne Rickard

                                   (Prior to Lease Commencement Date)

                                   and

                                   16241 Laguna Canyon Road
                                   Suite 100
                                   Irvine, California 92718
                                   Attention: Operations Manager

                                   with a copy to:

                                   5800 Hellyer Avenue
                                   San Jose, California 95138
                                   Attention:  Ms. Christine Munson
                                               Mr. Wayne Richard

                                   (After Lease Commencement Date)
</TABLE>

                                      -3-
<PAGE>   10

<TABLE>
<S>  <C>                           <C>
10.  Address of Landlord           c/o Sares-Regis Group
     (Section 29.18):              16277 Laguna Canyon Road, Suite G
                                   Irvine, California 92618
                                   Attention:  Property Manager

                                   and

                                   J.P. Morgan Investment Management
                                   522 Fifth Avenue
                                   New York, NY 10036
                                   Attention: Real Estate Investments,
                                              Irvine Oaks Asset Manager

                                   with a copy to:

                                   Sares-Regis Group
                                   18802 Bardeen Avenue
                                   Irvine, California 92612

                                   and

                                   (only as to notices of default and other legal
                                   notices) Allen, Matkins, Leck, Gamble & Mallory, LLP
                                   18400 Von Karman, Fourth Floor
                                   Irvine, California 92612-1597
                                   Attention: Paul O'Connor, Esq.

11.  Broker(s)                     CB Richard Ellis
     (Section 29.24):              2400 East Katella Avenue, 7th Floor
                                   Anaheim, California 92806-5938
                                   Attention:  Mr. Mark Friend

                                   and

                                   Lee & Associates
                                   15615 Alton Parkway, Suite 150
                                   Irvine, California 92618
                                   Attention: Mr. Randolph Mason
</TABLE>

                                      -4-
<PAGE>   11

                                    ARTICLE 1

                  PREMISES, BUILDING, PROJECT, AND COMMON AREAS

        1.1 PREMISES, BUILDING, PROJECT AND COMMON AREAS.

                1.1.1 THE PREMISES. Landlord hereby leases to Tenant and Tenant
hereby leases from Landlord the premises set forth in Section 2.2 of the Summary
(the "PREMISES"). The outline of the Premises is set forth in EXHIBIT A attached
hereto and the Premises contains the number of rentable square feet set forth in
Section 2.2 of the Summary. The parties hereto agree that the lease of the
Premises is upon and subject to the terms, covenants and conditions herein set
forth, and Tenant covenants as a material part of the consideration for this
Lease to keep and perform each and all of such terms, covenants and conditions
by it to be kept and performed and that this Lease is made upon the condition of
such performance. The parties hereto hereby acknowledge that the purpose of
EXHIBIT A is to show the approximate location of the Premises in the "Building,"
as that term is defined in Section 1.1.2, below, only, and such Exhibit is not
meant to constitute an agreement, representation or warranty as to the
construction of the Premises, the precise area thereof or the specific location
of the "Common Areas," as that term is defined in Section 1.1.3, below, or the
elements thereof or of the accessways to the Premises or the "Project," as that
term is defined in Section 1.1.2, below. Except as specifically set forth in
this Lease and in the Tenant Work Letter attached hereto as EXHIBIT B (the
"TENANT WORK LETTER"), Landlord shall not be obligated to provide or pay for any
improvement work or services related to the improvement of the Premises. Subject
to the provisions of Section 1 of the Tenant Work Letter, Tenant also
acknowledges that neither Landlord nor any agent of Landlord has made any
representation or warranty regarding the condition of the Premises, the Building
or the Project or with respect to the suitability of any of the foregoing for
the conduct of Tenant's business, except as specifically set forth in this Lease
and the Tenant Work Letter; provided, however, that Landlord warrants and
represents that as of the Lease Commencement Date, the electrical, mechanical,
HVAC, plumbing and other systems are in good working order and the roof of the
Building is water tight. The taking of possession of the Premises by Tenant
shall conclusively establish that the Premises and the Building were at such
time in good and sanitary order, condition and repair.

                1.1.2 THE BUILDING AND THE PROJECT. The Premises are a part of
the building set forth in Section 2.1 of the Summary (the "BUILDING"). The
Building is part of an office project known as "IRVINE OAKS EXECUTIVE PARK." The
term "PROJECT," as used in this Lease, shall mean (i) the Building and the
Common Areas, (ii) the land (which is improved with landscaping, parking areas
and other improvements) upon which the Building and the Common Areas are
located, and (iii) the other office buildings located within the Project and the
land upon which such adjacent office buildings are located.

                1.1.3 COMMON AREAS. Tenant shall have the non-exclusive right to
use in common with other tenants in the Project, and subject to the rules and
regulations referred to in Article 5 of this Lease, those portions of the
Project which are provided, from time to time, for use in common by Landlord,
Tenant and any other tenants of the Project (such areas, together with such
other

                                      -5-
<PAGE>   12

portions of the Project designated by Landlord, in its discretion, including
certain areas designated for the exclusive use of certain tenants, or to be
shared by Landlord and certain tenants, are collectively referred to herein as
the "COMMON AREAS"). The Common Areas shall consist of the "Project Common
Areas" and the "Building Common Areas." The term "PROJECT COMMON AREAS," as used
in this Lease, shall mean the portion of the Project designated as such by
Landlord. The term "BUILDING COMMON AREAS," as used in this Lease, shall mean
the portions of the Common Areas located within the Building designated as such
by Landlord. The manner in which the Common Areas are maintained and operated
shall be at the reasonable discretion of Landlord and the use thereof shall be
subject to such reasonable rules, regulations and restrictions as Landlord may
make from time to time. Landlord reserves the right to close temporarily, make
alterations or additions to, or change the location of elements of the Project
and the Common Areas (the "Landlord Work"); provided, however, that Landlord
shall use commercially reasonable efforts to minimize any interference with
Tenant's business caused by the performance of such Landlord Work.

        1.2 VERIFICATION OF RENTABLE SQUARE FEET OF PREMISES, BUILDING, AND
PROJECT. For purposes of this Lease, "RENTABLE SQUARE FEET" and "usable square
feet" shall be deemed to be as set forth in Section 2.2 of the Summary, and
shall not be subject to remeasurement during the Lease Term. In the event that
the rentable area of the Premises, the Building and/or the Project shall change
due to such verification, or due to subsequent alterations and/or other
modifications to the Premises, the Building and/or the Project, the rentable
area of the Premises, the Building and/or the Project, as the case may be, shall
be appropriately adjusted as of the date of such alteration and/or other
modification, based upon the written verification by Landlord's space planner of
such revised rentable area. In the event of any such adjustment to the rentable
area of the Premises, the Building and/or the Project, all amounts, percentages
and figures appearing or referred to in this Lease based upon such rentable area
(including, without limitation, the amount of the "Rent" and any "Security
Deposit," as those terms are defined in Article 4 and Article 21 of this Lease,
respectively and "Tenant's Project Share," as that term is defined in Section
4.2.10, below) shall be modified in accordance with such determination.

                                    ARTICLE 2

                         INITIAL LEASE TERM; OPTION TERM

        2.1 INITIAL LEASE TERM. The terms and provisions of this Lease shall be
effective as of the date of this Lease. The term of this Lease (the "LEASE
TERM") shall be as set forth in Section 3.1 of the Summary, shall commence on
the date set forth in Section 3.2 of the Summary (the "LEASE COMMENCEMENT
DATE"), and shall terminate on the date set forth in Section 3.3 of the Summary
(the "LEASE EXPIRATION DATE") unless this Lease is sooner terminated as
hereinafter provided. For purposes of this Lease, the term "LEASE YEAR" shall
mean each consecutive twelve (12) month period during the Lease Term. At any
time during the Lease Term, Landlord may deliver to Tenant a notice in the form
as set forth in EXHIBIT C, attached hereto, as a confirmation only of the
information set forth therein, which Tenant shall execute and return to Landlord
within five (5) days of receipt thereof.

                                      -6-
<PAGE>   13

        2.2 OPTION TERM.

                2.2.1 OPTION RIGHT. Landlord hereby grants to the Tenant
originally named in the Summary and any "Affiliates" (as that term is defined in
Section 14.8, below) (the Tenant and Affiliates shall be collectively referred
to herein as the "ORIGINAL TENANT") one (1) option to extend the Lease Term for
a period of three (3) years (the "OPTION TERM"), which option shall be
exercisable only by written notice delivered by Tenant to Landlord as provided
below, provided that, as of the date of delivery of such notice, Tenant is not
in default under this Lease. Upon the proper exercise of such option to extend,
and provided that, as of the end of the initial Lease Term, Tenant is not in
default under this Lease, the Lease Term, as it applies to the Premises, shall
be extended for a period of three (3) years. The rights contained in this
Section 2.2 shall be personal to the Original Tenant and may only be exercised
by the Original Tenant (and not any other assignee, sublessee or other
transferee of the Original Tenant's interest in this Lease) if the Original
Tenant occupies the entire Premises.

                2.2.2 OPTION RENT. The rent payable by Tenant during the Option
Term (the "OPTION RENT") shall be equal to the annual rental rate per rentable
square foot (and the additional rent and considering any "base year" or "expense
stop" applicable thereto) at which, as of the commencement of the Option Term,
tenants are leasing non-sublease, non-encumbered, non-equity space comparable in
size, location and quality to the Premises, for a term of five (5) years, which
comparable space is located in the Project, taking into consideration the
following concessions: (a) rental abatement concessions, if any, being granted
such tenants in connection with such comparable space; and (b) tenant
improvements or allowances provided or to be provided for such comparable space,
taking into account, and deducting the value of, the existing improvements in
the Premises, such value to be based upon the age, quality and layout of the
improvements and the extent to which the same could be utilized by a general
office user.

                2.2.3 EXERCISE OF OPTION. The option contained in this Section
2.2 shall be exercised by Tenant, if at all, only in the following manner: (i)
Tenant shall deliver written notice to Landlord not more than twelve (12) months
nor less than nine (9) months prior to the expiration of the initial Lease Term,
stating that Tenant is interested in exercising its option; (ii) Landlord, after
receipt of Tenant's notice, shall deliver notice (the "OPTION RENT NOTICE") to
Tenant not less than eight (8) months prior to the expiration of the initial
Lease Term, setting forth the Option Rent; and (iii) if Tenant wishes to
exercise such option, Tenant shall, on or before the earlier of (A) the date
occurring seven (7) months prior to the expiration of the initial Lease Term,
and (B) the date occurring thirty (30) days after Tenant's receipt of the Option
Rent Notice, exercise the option by delivering written notice thereof to
Landlord, and concurrently therewith, Tenant may object to the Option Rent set
forth in the Option Rent Notice, in which case the Option Rent shall be
determined as set forth in Section 2.2.4, below.

                2.2.4 DETERMINATION OF OPTION RENT. In the event Tenant timely
and appropriately objects to the Option Rent, Landlord and Tenant shall attempt
to agree upon the Option Rent using their best good-faith efforts. If Landlord
and Tenant fail to reach agreement within ten (10) days following Tenant's
objection to the Option Rent, (the "OUTSIDE AGREEMENT DATE"), then each party

                                      -7-
<PAGE>   14

shall make a separate determination of the Option Rent, as the case may be
within five (5) days, and such determinations shall be submitted to arbitration
in accordance with Section 2.2.4.1 through 2.2.4.7, below.

                        2.2.4.1 Landlord and Tenant shall each appoint one
arbitrator who shall by profession be a real estate broker or appraiser who
shall have been active over the five (5) year period ending on the date of such
appointment in the leasing (or appraisal, as the case may be) of commercial
properties in the Irvine area. The determination of the arbitrators shall be
limited solely to the issue area of whether Landlord's or Tenant's submitted
Option Rent, is the closest to the actual Option Rent as determined by the
arbitrators, taking into account the requirements of Section 2.2.2. Each such
arbitrator shall be appointed within fifteen (15) days after the applicable
Outside Agreement Date.

                        2.2.4.2 The two arbitrators so appointed shall within
ten (10) days of the date of the appointment of the last appointed arbitrator
agree upon and appoint a third arbitrator who shall be qualified under the same
criteria set forth hereinabove for qualification of the initial two arbitrators.

                        2.2.4.3 The three arbitrators shall within thirty (30)
days of the appointment of the third arbitrator reach a decision as to whether
the parties shall use Landlord's or Tenant's submitted Option Rent, and shall
notify Landlord and Tenant thereof.

                        2.2.4.4 The decision of the majority of the three
arbitrators shall be binding upon Landlord and Tenant.

                        2.2.4.5 If either Landlord or Tenant fails to appoint an
arbitrator within 15 days after the applicable Outside Agreement Date, the
arbitrator appointed by one of them shall reach a decision, notify Landlord and
Tenant thereof, and such arbitrator's decision shall be binding upon Landlord
and Tenant.

                        2.2.4.6 If the two arbitrators fail to agree upon and
appoint a third arbitrator, or both parties fail to appoint an arbitrator, then
the appointment of the third arbitrator or any arbitrator shall be dismissed and
the matter to be decided shall be forthwith submitted to arbitration under the
provisions of the American Arbitration Association, but subject to the
instruction set forth in this Section 2.2.4.

                        2.2.4.7 The cost of arbitration shall be paid by
Landlord and Tenant equally.

                                    ARTICLE 3

                                    BASE RENT

        Tenant shall pay, without prior notice or demand, to Landlord or
Landlord's agent at the management office of the Project, or, at Landlord's
option, at such other place as Landlord may from time to time designate in
writing, by a check for currency which, at the time of payment, is legal

                                      -8-
<PAGE>   15

tender for private or public debts in the United States of America, base rent
("BASE RENT") as set forth in Section 4 of the Summary, payable in equal monthly
installments as set forth in Section 4 of the Summary in advance on or before
the first day of each and every calendar month during the Lease Term, without
any setoff or deduction whatsoever. Notwithstanding the foregoing, Tenant is
excused from its obligation to pay any Base Rent attributable to the first (1st)
month of the Lease Term ("EARLY OCCUPANCY PERIOD"). Tenant shall still be
responsible for the payment of Additional Rent, as that term is defined in
Article 4 below, during such Early Occupancy Period. The Base Rent for the first
full month of the Lease Term which occurs after the expiration of the Early
Occupancy Period shall be paid at the time of Tenant's execution of this Lease
along with the Estimated Building Direct Expenses and Project Direct Expenses
for the first month of the Lease Tenn. If any Rent payment date (including the
Lease Commencement Date) falls on a day of the month other than the first day of
such month or if any payment of Rent is for a period which is shorter than one
month, the Rent for any fractional month shall accrue on a daily basis for the
period from the date such payment is due to the end of such calendar month or to
the end of the Lease Term at a rate per day which is equal to 1/365 of the
applicable annual Rent. All other payments or adjustments required to be made
under the terms of this Lease that require proration on a time basis shall be
prorated on the same basis.

                                    ARTICLE 4

                                 ADDITIONAL RENT

        4.1 GENERAL TERMS. In addition to paying the Base Rent specified in
Article 3 of this Lease, Tenant shall pay "Tenant's Building Share" of the
annual "Building Direct Expenses," and "Tenant's Project Share" of the annual
"Project Direct Expenses" as those terms are defined in Section 4.2, below. Such
payments by Tenant, together with any and all other amounts payable by Tenant to
Landlord pursuant to the terms of this Lease, are hereinafter collectively
referred to as the "ADDITIONAL RENT", and the Base Rent and the Additional Rent
are herein collectively referred to as "RENT." All amounts due under this
Article 4 as Additional Rent shall be payable for the same periods and in the
same manner as the Base Rent. Without limitation on other obligations of Tenant
which survive the expiration of the Lease Term, the obligations of Tenant to pay
the Additional Rent provided for in this Article 4 shall survive the expiration
of the Lease Term.

        4.2 DEFINITIONS OF KEY TERMS RELATING TO ADDITIONAL RENT. As used in
this Article 4, the following terms shall have the meanings hereinafter set
forth:

                4.2.1 "PROJECT DIRECT EXPENSES" shall mean the portion of
"Direct Expenses," as that term is defined in Section 4.2.5 below, which is not
attributable to any particular Building in the Project, but which instead
relates to the Project as a whole.

                4.2.2 "BUILDING DIRECT EXPENSES" shall mean "Building Operating
Expenses" and "Building Tax Expenses", as those terms are defined in Sections
4.2.3 and 4.2.4, below, respectively.

                                      -9-
<PAGE>   16

                4.2.3 "BUILDING OPERATING EXPENSES" shall mean the portion of
"Operating Expenses," as that term is defined in Section 4.2.7 below, allocated
to the tenants of the Building pursuant to the terms of Section 4.3.1 below.

                4.2.4 "BUILDING TAX EXPENSES" shall mean that portion of "Tax
Expenses", as that term is defined in Section 4.2.8 below, allocated to the
tenants of the Building pursuant to the terms of Section 4.3.1 below.

                4.2.5 "DIRECT EXPENSES" shall mean "Operating Expenses" and "Tax
Expenses."

                4.2.6 "EXPENSE YEAR" shall mean each calendar year in which any
portion of the Lease Term falls, through and including the calendar year in
which the Lease Term expires, provided that Landlord, upon notice to Tenant, may
change the Expense Year from time to time to any other twelve (12) consecutive
month period, and, in the event of any such change, Tenant's Share of Building
Direct Expenses shall be equitably adjusted for any Expense Year involved in any
such change, provided that there shall be no increase in the total amount of the
Building Direct Expenses payable by Tenant under this Lease.

                4.2.7 "OPERATING EXPENSES" shall mean all expenses, costs and
amounts of every kind and nature which Landlord pays or accrues during any
Expense Year because of or in connection with the ownership, management,
maintenance, security, repair, replacement, restoration or operation of the
Project, or any portion thereof. Without limiting the generality of the
foregoing, Operating Expenses shall specifically include any and all of the
following: (i) the cost of supplying all utilities, the cost of operating,
repairing, maintaining, and renovating the utility, telephone, mechanical,
sanitary, storm drainage, and elevator systems, and the cost of maintenance and
service contracts in connection therewith; (ii) the cost of licenses,
certificates, permits and inspections and the cost of contesting any
governmental enactments which may affect Operating Expenses, and the costs
incurred in connection with a transportation system management program or
similar program; (iii) the cost of all insurance carried by Landlord in
connection with the Project as reasonably determined by Landlord; (iv) the cost
of landscaping, relamping, and all supplies, tools, equipment and materials used
in the operation, repair and maintenance of the Project, or any portion thereof,
(v) the cost of parking area repair, restoration, and maintenance; (vi) fees and
other costs, including management fees, consulting fees, legal fees and
accounting fees, of all contractors and consultants in connection with the
management, operation, maintenance and repair of the Project; (vii) payments
under any equipment rental agreements and the fair rental value of any
management office space; (viii) wages, salaries and other compensation and
benefits, including taxes levied thereon, of all persons engaged in the
operation, maintenance and security of the Project; (ix) costs under any
instrument pertaining to the sharing of costs by the Project; (x) operation,
repair, maintenance and replacement of all systems and equipment and components
thereof of the Building; (xi) the cost of janitorial, alarm, security and other
services, replacement of wall and floor coverings, ceiling tiles and fixtures in
common areas, maintenance and replacement of curbs and walkways, repair to roofs
and re-roofing; (xii) amortization (including interest on the unamortized cost)
of the cost of acquiring or the rental expense of personal property used in the
maintenance, operation and repair of the Project, or any portion thereof; (xiii)
the cost of capital improvements or other costs incurred in

                                      -10-
<PAGE>   17

connection with the Project (A) which are intended to effect economies in the
operation or maintenance of the Project, or any portion thereof, (B) that are
required to comply with present or anticipated conservation programs, (C) which
are replacements or modifications of nonstructural items located in the Common
Areas required to keep the Common Areas in good order or condition, (D) that are
required under any governmental law or regulation or (E) which are reasonably
determined by Landlord to be in the best interests of the Building and/or the
Project; provided, however, that any capital expenditure shall be amortized over
its useful life as Landlord shall reasonably determine, and the unamortized cost
of the same shall bear interest at the rate of ten percent (10%) per annum or
such higher rate as was paid by Landlord on funds borrowed for the purpose of
purchasing, installing, and constructing such capital improvements; and (xiv)
costs, fees, charges or assessments imposed by, or resulting from any mandate
imposed on Landlord by, any federal, state or local government for fire and
police protection, trash removal, community services, or other services which do
not constitute "Tax Expenses" as that term is defined in Section 4.2.8, below.
Notwithstanding anything to the contrary in this Lease, Operating Expenses shall
not include, and Tenant shall have no obligation to pay, perform or reimburse
Landlord for all or any portion of the following:

        (a) costs, including marketing costs, legal fees, space planners' fees,
advertising and promotional expenses, and brokerage fees incurred in connection
with the original construction or development, or original or future leasing of
the Project, and costs, including permit, license and inspection costs, incurred
with respect to the installation of tenant improvements made for tenants in the
Project (other than Tenant) or incurred in renovating or otherwise improving,
decorating, painting or redecorating any portion of the Project for tenants or
other occupants of the Project (excluding, however, such costs relating to any
common areas of the Project or parking facilities which benefit all Project
tenants);

        (b) except as set forth in items (xii) and (xiii) above, depreciation,
interest and principal payments on mortgages and other debt costs, if any,
penalties and interest, costs of capital repairs and alterations, and costs of
capital improvements and equipment;

        (c) amount paid as ground rental for the Project by the Landlord;

        (d) rentals and other related expenses incurred in leasing air
conditioning systems, elevators or other equipment which if purchased the cost
of which would be excluded from Operating Expenses as a capital cost, except
equipment not affixed to the Project which is used in providing janitorial or
similar services and, further excepting from this exclusion such equipment
rented or leased to remedy or ameliorate an emergency condition in the Project;

        (e) costs arising from the negligence or wilful misconduct of Landlord
or its agents, employees, vendors, contractors, or providers of materials or
services;

        (f) costs incurred to comply with laws relating to the removal of
hazardous material (as defined under applicable law) and asbestos containing
material (collectively, "HAZARDOUS MATERIAL") which was in existence in the
Building or on the Project prior to the Lease Commencement Date, and was of such
a nature that a federal, State or municipal governmental

                                      -11-
<PAGE>   18

authority, if it had then had knowledge of the presence of such Hazardous
Material, in the state, and under the conditions that it then existed in the
Building or on the Project, would have then required the removal of such
Hazardous Material or other remedial or containment action with respect thereto;
and costs incurred to remove, remedy, contain, or treat Hazardous Material,
which Hazardous Material is brought into the Building or onto the Project after
the date hereof by anyone other than Tenant or Tenant's Affiliates, Landlord or
any other tenant of the Project and is of such a nature, at that time, that a
federal, State or municipal governmental authority, if it had then had knowledge
of the presence of such Hazardous Material, in the state, and under the
conditions, that it then exists in the Building or on the Project, would have
then required the removal of such Hazardous Material or other remedial or
containment action with respect thereto;

        (g) marketing costs, including, but not limited to, leasing commissions,
attorneys' fees and court costs in connection with the negotiation and
preparation of letters, deal memos, letters of intent, leases, subleases and/or
assignments, space planning costs, and other costs and expenses incurred in
connection with lease, sublease and/or assignment negotiations and transactions
with present or prospective tenants or other occupants of the Building,
including attorneys' fees and other costs and expenditures incurred in
connection with disputes with present or prospective tenants or other occupants
of the Building; and

        (h) costs incurred due to a violation by Landlord or any tenant or
occupant (other than Tenant) of any term or condition of any lease or rental
arrangement covering space in the Project.

        (i) costs incurred in connection with the original construction of the
Building or in connection with any major change in the Building, such as adding
or deleting floors;

        (j) costs of capital repairs and alterations, capital improvements and
equipment except as set forth in items (xi) and (xiii), above; and

        (k) costs of a capital nature (capital repairs and/or capital
replacements) to repair or rebuild after a casualty loss (excluding deductibles
under insurance policies carried by Landlord).

        If the Project is not at least ninety-five percent (95%) occupied during
all or a portion of or any Expense Year, Landlord may elect to make an
appropriate adjustment to the components of Operating Expenses for such year to
determine the amount of Operating Expenses that would have been paid had the
Project been ninety-five percent (95%) occupied; and the amount so determined
shall be deemed to have been the amount of Operating Expenses for such year.

                4.2.8 TAXES.

                        4.2.8.1 "TAX EXPENSES" shall mean all federal, state,
county, or local governmental or municipal taxes, fees, charges or other
impositions of every kind and nature, whether general, special, ordinary or
extraordinary, (including, without limitation, real estate taxes, general and
special assessments, transit taxes, leasehold taxes or taxes based upon the
receipt of rent, including gross receipts or sales taxes applicable to the
receipt of rent, unless required to be paid by Tenant, personal property taxes
imposed upon the fixtures, machinery, equipment, apparatus,

                                      -12-
<PAGE>   19

systems and equipment, appurtenances, furniture and other personal property used
in connection with the Project, or any portion thereof), which shall be paid or
accrued during any Expense Year (without regard to any different fiscal year
used by such governmental or municipal authority) because of or in connection
with the ownership, leasing and operation of the Project, or any portion
thereof.

                        4.2.8.2 Tax Expenses shall include, without limitation:
(i) Any tax on the rent, right to rent or other income from the Project, or any
portion thereof, or as against the business of leasing the Project, or any
portion thereof, (ii) Any assessment, tax, fee, levy or charge in addition to,
or in substitution, partially or totally, of any assessment, tax, fee, levy or
charge previously included within the definition of real property tax, it being
acknowledged by Tenant and Landlord that Proposition 13 was adopted by the
voters of the State of California in the June 1978 election ("PROPOSITION 13")
and that assessments, taxes, fees, levies and charges may be imposed by
governmental agencies for such services as fire protection, street, sidewalk and
road maintenance, refuse removal and for other governmental services formerly
provided without charge to property owners or occupants, and, in further
recognition of the decrease in the level and quality of governmental services
and amenities as a result of Proposition 13, Tax Expenses shall also include any
governmental or private assessments or the Project's contribution towards a
governmental or private cost-sharing agreement for the purpose of augmenting or
improving the quality of services and amenities normally provided by
governmental agencies; (iii) Any assessment, tax, fee, levy, or charge allocable
to or measured by the area of the Premises or the Rent payable hereunder,
including, without limitation, any business or gross income tax or excise tax
with respect to the receipt of such rent, or upon or with respect to the
possession, leasing, operating, management, maintenance, alteration, repair, use
or occupancy by Tenant of the Premises, or any portion thereof; and (iv) Any
assessment, tax, fee, levy or charge, upon this transaction or any document to
which Tenant is a party, creating or transferring an interest or an estate in
the Premises. Tax Expenses in the Base Year will reflect any increased
assessments resulting from the most recent sale of the Project.

                        4.2.8.3 Any costs and expenses (including, without
limitation, reasonable attorneys' fees) incurred in attempting to protest,
reduce or minimize Tax Expenses shall be included in Tax Expenses in the Expense
Year such expenses are paid. Tax refunds shall be credited against Tax Expenses
and refunded to Tenant regardless of when received, based on the Expense Year to
which the refund is applicable, provided that in no event shall the amount to be
refunded to Tenant for any such Expense Year exceed the total amount paid by
Tenant as Additional Rent under this Article 4 for such Expense Year. If Tax
Expenses for any period during the Lease Term or any extension thereof are
increased after payment thereof for any reason, including, without limitation,
error or reassessment by applicable governmental or municipal authorities,
Tenant shall pay Landlord upon demand Tenant's Share of any such increased Tax
Expenses included by Landlord as Building Tax Expenses pursuant to the terms of
this Lease. Notwithstanding anything to the contrary contained in this Section
4.2.8 (except as set forth in Section 4.2.8.1, above), there shall be excluded
from Tax Expenses (i) all excess profits taxes, franchise taxes, gift taxes,
capital stock taxes, inheritance and succession taxes, estate taxes, federal and
state income taxes, and other taxes to the extent applicable to Landlord's
general or net income (as opposed to rents, receipts or income

                                      -13-
<PAGE>   20

attributable to operations at the Project, (ii) any items included as Operating
Expenses, and (iii) any items paid by Tenant under Section 4.5 of this Lease.

                        4.2.8.4 EXCLUDED TAXES. Notwithstanding anything to the
contrary contained in this Section 4.2.8 (except as set forth in Section
4.2.8.2, above), there shall be excluded from Tax Expenses (i) all excess
profits taxes, franchise taxes, gift taxes, capital stock taxes, inheritance and
succession taxes, estate taxes, federal and state income taxes, and other taxes
to the extent applicable to Landlord's general or net income (as opposed to
rents, receipts or income attributable to operations at the Project), (ii) any
items included as Operating Expenses, (iii) any cost that is excluded from
Operating Expenses, and (iv) any items paid by Tenant under Section 4.5 of this
Lease.

                4.2.9 "TENANT'S BUILDING SHARE" shall mean the percentage set
forth in Section 6.1 of the Summary.

                4.2.10 "TENANT'S PROJECT SHARE" "Tenant's Project Share" shall
mean the percentage set forth in Section 5.2 of the Summary.

        4.3 ALLOCATION OF DIRECT EXPENSES.

                4.3.1 METHOD OF ALLOCATION. The parties acknowledge that the
Building is a part of a multi-building project and that the Project Direct
Expenses should be shared between the tenants of the Building and the tenants of
the other buildings in the Project. Accordingly, as set forth in Section 4.2
above, Direct Expenses (which consists of Operating Expenses and Tax Expenses)
are determined annually for the Project as a whole, and a portion of the Direct
Expenses, which portion shall be determined by Landlord on an equitable basis,
shall be allocated to the tenants of the Building (as opposed to the tenants of
any other buildings in the Project) and such portion shall be the Building
Direct Expenses for purposes of this Lease. Such portion of Direct Expenses
allocated to the tenants of the Building shall include all Direct Expenses
attributable solely to the Building.

                4.3.2 COST POOLS. Landlord shall have the right, from time to
time, to equitably allocate some or all of the Project Direct Expenses among
different portions or occupants of the Project (the "COST POOLS"), in Landlord's
reasonable, good faith discretion. Such Cost Pools may include, but shall not be
limited to, the office space tenants of a building of the Project or of the
Project, and the retail space tenants of a building of the Project or of the
Project. The Direct Expenses within each such Cost Pool shall be allocated and
charged to the tenants within such Cost Pool in an equitable manner.

        4.4 CALCULATION AND PAYMENT OF ADDITIONAL RENT. For each Expense Year
ending or commencing within the Lease Term, Tenant shall pay to Landlord, in the
manner set forth in Section 4.4.1, below, and as Additional Rent, an amount
equal to the sum of (i) Tenant's Share of Building Direct Expenses for such
Expense Year and (ii) Tenant's Project Share of Project Direct Expenses for such
Expense Year (collectively, the "EXPENSE PAYMENT").

                                      -14-
<PAGE>   21

                4.4.1 STATEMENT OF ACTUAL DIRECT EXPENSES AND PAYMENT BY TENANT.
Landlord shall give to Tenant following the end of each Expense Year, a
statement (the "STATEMENT") which shall state the Building Direct Expenses and
Project Direct Expenses incurred or accrued for such preceding Expense Year, and
which shall indicate the amount of the Expense Payment. Upon receipt of the
Statement for each Expense Year commencing or ending during the Lease Term,
Tenant shall pay, with its next installment of Base Rent due, the full amount of
the Expense Payment for such Expense Year, less the amounts, if any, paid during
such Expense Year as an "Estimated Payment," as that term is defined in Section
4.4.2, below; provided however, that in the event that the amounts paid by
Tenant as an Estimated Payment exceed the actual Expense Payments for such
Expense Year (the "Excess"), such Excess shall be credited by Landlord to the
Estimated Payments due for the following Expense Year. The failure of Landlord
to timely furnish the Statement for any Expense Year shall not prejudice
Landlord or Tenant from enforcing its rights under this Article 4. Even though
the Lease Term has expired and Tenant has vacated the Premises, when the final
determination is made of Tenant's Building Share of Building Direct Expenses and
Tenant's Project Share of Project Direct Expenses for the Expense Year in which
this Lease terminates either (i) Tenant shall immediately pay to Landlord such
amount or (ii) Landlord shall refund any Excess payments to Tenant within thirty
(30) days of such determination. The provisions of this Section 4.4.1 shall
survive the expiration or earlier termination of the Lease Term.

                4.4.2 STATEMENT OF ESTIMATED DIRECT EXPENSES. In addition,
Landlord shall give Tenant a yearly expense estimate statement (the "ESTIMATE
STATEMENT") which shall set forth Landlord's reasonable estimate (the
"ESTIMATE") of what the total amount of Building Direct Expenses and Project
Direct Expenses for the then-current Expense Year shall be and the estimated
payment (the "ESTIMATED PAYMENT") which shall be based upon the Estimate. The
failure of Landlord to timely furnish the Estimate Statement for any Expense
Year shall not preclude Landlord from enforcing its rights to collect any
Estimated Payment under this Article 4, nor shall Landlord be prohibited from
revising any Estimate Statement or Estimated Payment theretofore delivered to
the extent necessary. Thereafter, Tenant shall pay, with its next installment of
Base Rent due, a fraction of the Estimated Payment for the then-current Expense
Year (reduced by any amounts paid pursuant to the next to last sentence of this
Section 4.4.2). Such fraction shall have as its numerator the number of months
which have elapsed in such current Expense Year, including the month of such
payment, and twelve (12) as its denominator. Until a new Estimate Statement is
furnished (which Landlord shall have the right to deliver to Tenant at any
time), Tenant shall pay monthly, with the monthly Base Rent installments, an
amount equal to one-twelfth (1/12) of the total Estimated Payment set forth in
the previous Estimate Statement delivered by Landlord to Tenant. Landlord shall
maintain books and records with respect to Building Direct Expenses and Project
Direct Expenses in accordance with generally accepted accounting and management
practices, consistently applied.

        4.5 TAXES AND OTHER CHARGES FOR WHICH TENANT IS DIRECTLY RESPONSIBLE.

                4.5.1 PERSONAL PROPERTY TAXES. Tenant shall be liable for and
shall pay at least ten (10) days before delinquency, taxes levied against
Tenant's equipment, furniture, fixtures and any other personal property located
in or about the Premises. If any such taxes on Tenant's equipment,

                                      -15-
<PAGE>   22

furniture, fixtures and any other personal property are levied against Landlord
or Landlord's property or if the assessed value of Landlord's property is
increased by the inclusion therein of a value placed upon such equipment,
furniture, fixtures or any other personal property and if Landlord pays the
taxes based upon such increased assessment, which Landlord shall have the right
to do regardless of the validity thereof but only under proper protest if
requested by Tenant, Tenant shall upon demand repay to Landlord the taxes so
levied against Landlord or the proportion of such taxes resulting from such
increase in the assessment, as the case may be.

                4.5.2 "ABOVE-STANDARD" IMPROVEMENTS. If the tenant improvements
in the Premises, whether installed and/or paid for by Landlord or Tenant and
whether or not affixed to the real property so as to become a part thereof, are
assessed for real property tax purposes at a valuation higher than the valuation
at which tenant improvements conforming to Landlord's "building standard" in
other space in the Building are assessed, then the Tax Expenses levied against
Landlord or the property by reason of such excess assessed valuation shall be
deemed to be taxes levied against personal property of Tenant and shall be
governed by the provisions of Section 4.5.1, above.

                4.5.3 OTHER TAXES. Notwithstanding any contrary provision
herein, and not including any transfer tax based on Landlord's sale of the
Property, Tenant shall pay prior to delinquency any (i) rent tax or sales tax,
service tax, transfer tax or value added tax, or any other applicable tax on the
rent or services of Landlord herein or otherwise respecting this Lease, (ii)
taxes assessed upon or with respect to the possession, leasing, operation,
management, maintenance, alteration, repair, use or occupancy by Tenant of the
Premises or any portion of the Project, including the Project parking facility;
or (iii) taxes assessed upon this transaction or any document to which Tenant is
a party creating or transferring an interest or an estate in the Premises for
the benefit of Tenant.

                4.5.4 SERVICE CHARGES. To the extent that Landlord provides any
services directly to Tenant, including, without limitation, janitorial,
locksmithing, lamp replacement, or repair and maintenance services, Tenant shall
pay to Landlord, as Additional Rent and concurrently with Tenant's payment of
Base Rent to Landlord, the sum of all costs of Landlord of such services, plus
an administration fee.

                                    ARTICLE 5

                                 USE OF PREMISES

        5.1 PERMITTED USE. Tenant shall use the Premises solely for the
Permitted Use set forth in Section 6 of the Summary and Tenant shall not use or
permit the Premises or the Project to be used for any other purpose or purposes
whatsoever without the prior written consent of Landlord, which may be withheld
in Landlord's sole discretion.

        5.2 PROHIBITED USES. Tenant further covenants and agrees that Tenant
shall not use, or suffer or permit any person or persons to use, the Premises or
any part thereof for any use or purpose contrary to the provisions of the Rules
and Regulations, which Rules and Regulations shall be enforced in a reasonable
and non-discriminatory manner in accordance with the provisions set forth

                                      -16-
<PAGE>   23

in EXHIBIT D, attached hereto, or in violation of the laws of the United States
of America, the State of California, or the ordinances, regulations or
requirements of the local municipal or county governing body or other lawful
authorities having jurisdiction over the Project) including, without limitation,
any such laws, ordinances, regulations or requirements relating to hazardous
materials or substances, as those terms are defined by applicable laws now or
hereafter in effect. Tenant shall not do or permit anything to be done in or
about the Premises which will in any way damage the reputation of the Project or
obstruct or interfere with the rights of other tenants or occupants of the
Building, or injure or unreasonably annoy them or use or allow the Premises to
be used for any improper, unlawful or objectionable purpose, nor shall Tenant
cause, maintain or permit any nuisance in, on or about the Premises. Tenant
shall comply with all recorded covenants, conditions, and restrictions now or
hereafter affecting the Project.

                                    ARTICLE 6

                             SERVICES AND UTILITIES

        6.1 STANDARD TENANT SERVICES. Landlord shall provide the following
services on all days (unless otherwise stated below) during the Lease Term.

                6.1.1 Landlord shall provide adequate electrical wiring and
facilities for connection to Tenant's lighting fixtures and incidental use
equipment, provided that the combined connected electrical load of the
incidental use equipment and lighting fixtures does not exceed an average of
eight (8) watts per usable square foot of the Premises during the Building Hours
on a monthly basis, and the electricity so furnished will be at a nominal one
hundred twenty (120) volts, (except as otherwise provided in the Approved
Working Drawings) and no electrical circuit for the supply of such incidental
use equipment will require a current capacity exceeding twenty (20) amperes,
which electrical usage shall be subject to applicable laws and regulations,
including Title 24. Tenant shall bear the cost of replacement of lamps, starters
and ballasts for lighting fixtures within the Premises.

                6.1.2 Landlord shall provide city water from the regular
Building outlets for drinking, lavatory and toilet purposes in the Building
Common Areas.

                6.1.3 Landlord shall provide exterior window washing services in
a manner consistent with other comparable buildings in the vicinity of the
Building.

                6.1.4 Landlord shall not provide janitorial services for the
Premises. Tenant shall be solely responsible for the maintenance of the Premises
in a manner consistent with a first-class office building and in connection
therewith, shall hire the service companies listed below, which service
companies shall carry insurance coverage in accordance with industry standards.

                        6.1.4.1 Tenant shall cause the carpets or other floor
coverings in the Premises to be professionally cleaned at least once every three
(3) months during the Lease Term.

                        6.1.4.2 Tenant shall cause to be provided (i) quarterly
interior window washing, and (ii) daily sweeping and cleaning of the Premises.

                                      -17-
<PAGE>   24

        Tenant shall cooperate fully with Landlord at all times and abide by all
regulations and requirements that Landlord may reasonably prescribe for the
proper functioning and protection of the HVAC, electrical, mechanical and
plumbing systems.

        6.2 OVERSTANDARD TENANT USE. Tenant shall not, without Landlord's prior
written consent, use heat-generating machines, machines other than normal
fractional horsepower office machines, or equipment or lighting other than
Building standard lights in the Premises, which may affect the temperature
otherwise maintained by the air conditioning system or increase the water
normally furnished for the Premises by Landlord pursuant to the terms of Section
6.1 of this Lease. If Tenant uses water, electricity, heat or air conditioning
in excess of that supplied by Landlord pursuant to Section 6.1 of this Lease,
Tenant shall pay to Landlord, upon billing, the reasonable cost of such excess
consumption, the reasonable cost of the installation, operation, and maintenance
of equipment which is installed in order to supply such excess consumption, and
the reasonable cost of the increased wear and tear on existing equipment caused
by such excess consumption; and Landlord may install devices to separately meter
any increased use and in such event Tenant shall pay the increased cost directly
to Landlord, on demand, at the rates charged by the public utility company
furnishing the same, including the cost of such additional metering devices.
Tenant's use of electricity shall never exceed the capacity of the feeders to
the Project or the risers or wiring installation.

        6.3 INTERRUPTION OF USE. Subject to the provisions of Section 19.5
below, Tenant agrees that Landlord shall not be liable for damages, by abatement
of Rent or otherwise, for failure to furnish or delay in furnishing any service
(including telephone and telecommunication services), or for any diminution in
the quality or quantity thereof, when such failure or delay or diminution is
occasioned, in whole or in part, by breakage, repairs, replacements, or
improvements, by any strike, lockout or other labor trouble, by inability to
secure electricity, gas, water, or other fuel at the Building or Project after
reasonable effort to do so, by any riot or other dangerous condition, emergency,
accident or casualty whatsoever, by act or default of Tenant or other parties,
or by any other cause beyond Landlord's reasonable control; and such failures or
delays or diminution shall never be deemed to constitute an eviction or
disturbance of Tenant's use and possession of the Premises or relieve Tenant
from paying Rent or performing any of its obligations under this Lease.
Furthermore, Landlord shall not be liable under any circumstances for a loss of,
or injury to, property or for injury to, or interference with, Tenant's
business, including, without limitation, loss of profits, however occurring,
through or in connection with or incidental to a failure to furnish any of the
services or utilities as set forth in this Article 6.

        6.4 SUBMETERING UTILITIES. In the event that the Premises are separately
metered for electricity, water, or any other utility service, Landlord shall
have the right to bill Tenant directly the cost of such utility, and Tenant
shall pay such costs directly to Landlord at the rates charged by the public
utility company furnishing the same, or to require Tenant to contract directly
with the applicable public utility for such service. Any such costs paid by
Tenant or any other tenant of the Building shall not be included in Operating
Expenses.

                                      -18-
<PAGE>   25

                                    ARTICLE 7

                                     REPAIRS

        Landlord shall maintain and repair the foundation, floor/ceiling slabs,
roof, curtain wall, exterior glass and mullions, columns, beams, shafts
(including elevator shafts), stairs, parking garage, stairwells, elevator cabs,
plazas, art work, sculptures, washrooms, and all common and public areas (the
"BUILDING STRUCTURES"), and the mechanical, electrical, life safety, plumbing,
sprinkler systems and HVAC systems which are not part of Tenant's improvements
or were not originally constructed by or for the benefit of Tenant or another
tenant (the "BUILDING SYSTEMS"). Tenant shall, at Tenant's own expense, keep the
Premises, including all improvements, fixtures and furnishings therein, and the
floor or floors of the Building on which the Premises are located, in good
order, repair and condition at all times during the Lease Term. In addition,
Tenant shall, at Tenant's own expense, but under the supervision and subject to
the prior approval of Landlord, and within any reasonable period of time
specified by Landlord, promptly and adequately repair all damage to the Premises
and replace or repair all damaged, broken, or worn fixtures and appurtenances,
except for damage caused by ordinary wear and tear or beyond the reasonable
control of Tenant; provided however, that, at Landlord's option, or if Tenant
fails to make such repairs, Landlord may, but need not, make such repairs and
replacements, and Tenant shall pay Landlord the reasonable cost thereof,
including a percentage of the cost thereof (to be uniformly established for the
Building and/or the Project) sufficient to reimburse Landlord for all overhead,
general conditions, fees and other costs or expenses arising from Landlord's
involvement with such repairs and replacements forthwith upon being billed for
same. Landlord may, but shall not be required to, enter the Premises at all
reasonable times and following reasonable notice to make such repairs,
alterations, improvements or additions to the Premises or to the Project or to
any equipment located in the Project as Landlord shall desire or deem necessary
or as Landlord may be required to do by governmental or quasi-governmental
authority or court order or decree. Tenant hereby waives any and all rights
under and benefits of subsection 1 of Section 1932 and Sections 1941 and 1942 of
the California Civil Code or under any similar law, statute, or ordinance now or
hereafter in effect. Any repair work by Landlord pursuant to the terms of this
Article 7 shall be conducted in a commercially reasonable manner so as to
minimize disruption to the business of Tenant in the Premises.

                                    ARTICLE 8

                            ADDITIONS AND ALTERATIONS

        8.1 LANDLORD'S CONSENT TO ALTERATIONS. Tenant shall have the right,
without Landlord's consent, but upon five (5) business days prior notice to
Landlord, to make non-structural additions and alterations ("NON-STRUCTURAL
ALTERATIONS") to the Premises that do not (i) involve the expenditure of more
than Ten Thousand and No/100 Dollars ($10,000.00) with respect to the work of
any particular Non-Structural Alteration, (ii) affect the exterior appearance of
the Building, (iii) affect the Building Systems or the Building Structure, or
(iv) violate law. Except in connection with Non-Structural Alterations, tenant
may not make any improvements, alterations, additions or changes to the Premises
or any mechanical, plumbing or HVAC facilities or systems pertaining to

                                      -19-
<PAGE>   26

the Premises (collectively, the "ALTERATIONS") without first procuring the prior
written consent of Landlord to such Alterations, which consent shall be
requested by Tenant not less than thirty (30) days prior to the commencement
thereof, and which consent shall not be unreasonably withheld by Landlord,
provided it shall be deeded reasonable for Landlord to withhold its consent to
any Alteration which adversely affects the structural portions or the systems or
equipment of the Building or is visible from the exterior of the Building. The
construction of the initial improvements to the Premises shall be governed by
the terms of the Tenant Work Letter and not the terms of this Article 8.

        8.2 MANNER OF CONSTRUCTION. Landlord may impose, as a condition of its
consent to any and all Alterations or repairs of the Premises or about the
Premises, such requirements as Landlord in its sole discretion may deem
desirable, including, but not limited to, the requirement that Tenant utilize
for such purposes only contractors, subcontractors, materials, mechanics and
materialmen selected by Tenant from a list of reputable candidates charging fair
market rates provided and approved by Landlord, and the requirement that upon
Landlord's written request given to Tenant prior to the installation of the
Alterations, Tenant shall, at Tenant's expense, remove such Alterations upon the
expiration or any early termination of the Lease Term. Tenant shall construct
such Alterations and perform such repairs in a good and workmanlike manner, in
conformance with any and all applicable federal, state, county or municipal
laws, rules and regulations and pursuant to a valid building permit, issued by
the City of Irvine, all in conformance with Landlord's reasonable construction
rules and regulations. In the event Tenant performs any Alterations in the
Premises which require or give rise to governmentally required changes to the
"Base Building," as that term is defined below, then Landlord shall, at Tenant's
expense, make such changes to the Base Building. The "BASE BUILDING" shall
include the structural portions of the Building, and the public restrooms and
the systems and equipment located in the internal core of the Building on the
floor or floors on which the Premises are located. In performing the work of any
such Alterations at the Premises, Tenant shall have the work performed in such
manner so as not to obstruct access to the Project or any portion thereof, by
any other tenant of the Project, and so as not to obstruct the business of
Landlord or other tenants in the Project. Tenant shall not use (and upon notice
from Landlord shall cease using) contractors, services, workmen, labor,
materials or equipment that, in Landlord's reasonable judgment, would disturb
labor harmony with the workforce or trades engaged in performing other work,
labor or services in or about the Building or the Common Areas. In addition to
Tenant's obligations under Article 9 of this Lease, upon completion of any
Alterations, Tenant agrees to cause a Notice of Completion to be recorded in the
office of the Recorder of the County of Orange in accordance with Section 3093
of the Civil Code of the State of California or any successor statute, and
Tenant shall deliver to the Project management office a reproducible copy of the
"as built" drawings of the Alterations as well as all permits, approvals and
other documents issued by any governmental agency in connection with the
Alterations.

        8.3 PAYMENT FOR IMPROVEMENTS. If payment is made directly to
contractors, Tenant shall comply with Landlord's requirements for final lien
releases and waivers in connection with Tenant's payment for work to
contractors. If Tenant orders any work directly from Landlord after the
Commencement Date of the Lease, Tenant shall pay to Landlord a percentage not to
exceed five percent (5%) of the cost of such work sufficient to compensate
Landlord for all overhead, general

                                      -20-
<PAGE>   27

conditions, fees and other costs and expenses arising from Landlord's
involvement with such work; provided however, that in the event Landlord's
involvement is limited to the review of Tenant's work performed by separate
contractors, Landlord shall be entitled to payment by Tenant of its reasonable
out-of-pocket expenses incurred in connection with such review.

        8.4 CONSTRUCTION INSURANCE. In connection with the construction of any
Alterations, Tenant shall comply with the terms of Section 10.3.4 regarding
Tenant's and its agents' insurance obligations.

        8.5 LANDLORD'S PROPERTY. All Alterations, improvements, fixtures,
equipment and/or appurtenances which may be installed or placed in or about the
Premises, from time to time, shall be at the sole cost of Tenant and shall be
and become the property of Landlord, except that Tenant may remove any
Alterations, improvements, fixtures and/or equipment which Tenant can
substantiate to Landlord have not been paid for with any Tenant improvement
allowance funds provided to Tenant by Landlord, provided Tenant repairs any
damage to the Premises and Building caused by such removal and returns the
affected portion of the Premises to a building standard tenant improved
condition as reasonably determined by Landlord. Furthermore, Landlord may, by
written notice to Tenant prior to the end of the Lease Term, or given following
any earlier termination of this Lease, require Tenant, at Tenant's expense, to
remove any Alterations as to which the notice requirement set forth in Section
8.2 above applies, and to repair any damage to the Premises and Building caused
by such removal and return the affected portion of the Premises to a building
standard tenant improved condition as reasonably determined by Landlord. If
Tenant fails to complete such removal and/or to repair any damage caused by the
removal of any Alterations and fails to return the affected portion of the
Premises to a building standard tenant improved condition as reasonably
determined by Landlord, Landlord may do so and may charge the reasonable cost
thereof to Tenant. Tenant hereby protects, defends, indemnifies and holds
Landlord harmless from any liability, cost, obligation, expense or claim of lien
in any manner relating to the installation, placement, removal or financing of
any such Alterations, improvements, fixtures and/or equipment in, on or about
the Premises, which obligations of Tenant shall survive the expiration or
earlier termination of this Lease.

                                    ARTICLE 9

                             COVENANT AGAINST LIENS

        Tenant shall keep the Project and Premises free from any liens or
encumbrances arising out of the work performed, materials furnished or
obligations incurred by or on behalf of Tenant, and shall protect, defend,
indemnify and hold Landlord harmless from and against any claims, liabilities,
judgments or costs (including, without limitation, reasonable attorneys' fees
and costs) arising out of same or in connection therewith. Tenant shall give
Landlord notice at least ten (10) days prior to the commencement of any such
work on the Premises (or such additional time as may be necessary under
applicable laws) to afford Landlord the opportunity of posting and recording
appropriate notices of non-responsibility. Tenant shall remove any such lien or
encumbrance by bond or otherwise within fifteen (15) days after notice by
Landlord, and if Tenant shall fail to do so, Landlord may pay the amount
necessary to remove such lien or encumbrance, without being

                                      -21-
<PAGE>   28

responsible for investigating the validity thereof. The amount so paid shall be
deemed Additional Rent under this Lease payable upon demand, without limitation
as to other remedies available to Landlord under this Lease. Nothing contained
in this Lease shall authorize Tenant to do any act which shall subject
Landlord's title to the Building or Premises to any liens or encumbrances
whether claimed by operation of law or express or implied contract. Any claim to
a lien or encumbrance upon the Building or Premises arising in connection with
any such work performed by or at the request of Tenant shall be null and void,
or at Landlord's option shall attach only against Tenant's interest in the
Premises and shall in all respects be subordinate to Landlord's title to the
Project, Building and Premises.

                                   ARTICLE 10

                                    INSURANCE

        10.1 INDEMNIFICATION AND WAIVER. Tenant hereby assumes all risk of
damage to property or injury to persons in or upon the Premises from any cause
whatsoever and agrees that Landlord, its partners, subpartners and their
respective officers, agents, servants, employees, and independent contractors
(collectively, "LANDLORD PARTIES") shall not be liable for, and are hereby
released from any responsibility for, any damage either to person or property or
resulting from the loss of use thereof, which damage is sustained by Tenant or
by other persons claiming through Tenant, except due to Landlord's negligence or
willful misconduct. Tenant shall indemnify, defend, protect, and hold harmless
the Landlord Parties from any and all loss, cost, damage, expense and liability
(including without limitation court costs and reasonable attorneys' fees)
incurred in connection with or arising from any cause in or on the Premises, any
acts, omissions or negligence of Tenant or of any person claiming by, through or
under Tenant, or of the contractors, agents, servants, employees, invitees,
guests or licensees of Tenant or any such person (collectively, "TENANT
PARTIES"), in or on the Project, or any breach of the terms of this Lease,
either during the Lease Term or any period of occupancy of the Premises by
Tenant prior to, during, or after the expiration of the Lease Term, provided
that the terms of the foregoing indemnity shall not apply to the negligence or
willful misconduct of Landlord or the Landlord Parties. Landlord shall not be
released or indemnified from and shall indemnify, defend, protect, and hold
harmless Tenant and the Tenant Parties from any and all loss, cost, damage,
expense and liability (including without limitation reasonable attorneys' fees)
arising from the negligence or willful misconduct of the Landlord Parties in or
on the Project or any breach by Landlord of its obligations under the Lease,
except to the extent caused by the negligence or willful misconduct of the
Tenant Parties. Notwithstanding anything to the contrary set forth in this
Lease, either party's agreement to indemnify the other party as set forth in
this Article 10, above, shall be ineffective to the extent the matters for which
such party agreed to indemnify the other party are covered by insurance required
to be carried by the other party pursuant to this Lease. Further, Tenant's
agreement to indemnify Landlord and Landlord's agreement to indemnify Tenant
pursuant to this Article 10 are not intended and shall not relieve any insurance
carrier of its obligations under policies required to be carried pursuant to the
provision of this Lease, to the extent such policies cover subject to the
parties' respective indemnification obligations; nor shall they supersede any
inconsistent agreement of the parties set forth in any other provision of this
Lease. Should Landlord be named as a defendant in any suit brought against
Tenant in connection with or arising out of any

                                      -22-
<PAGE>   29

claim to which Tenant's indemnity obligations apply, Tenant shall pay to
Landlord its costs and expenses incurred in such suit, including without
limitation, its actual professional fees such as appraisers', accountants' and
attorneys' fees. In addition, Tenant shall pay to Landlord any reasonable costs
and expenses, including without limitation, its actual attorney's fees, incurred
by Landlord in successfully enforcing Tenant's indemnity obligations set forth
in this Section 10.1. The provisions of this Section 10.1 shall survive the
expiration or sooner termination of this Lease with respect to any claims or
liability arising in connection with any event occurring prior to such
expiration or termination.

        10.2 TENANT'S COMPLIANCE WITH LANDLORD'S PROPERTY AND CASUALTY
INSURANCE. Landlord shall insure the base Building (including the Building
structure and Building systems) during the Lease Term against loss or damage due
to fire and other casualties covered within the classification of fire and
extended coverage, vandalism coverage and malicious mischief, sprinkler leakage,
water damage and special extended coverage. Additionally, at the option of
Landlord, such insurance coverage may include the risks of earthquakes and/or
flood damage and additional hazards, a rental loss endorsement and one or more
loss payee endorsements in favor of the holders of any mortgages or deeds of
trust encumbering the interest of Landlord in the Building or the ground or
underlying lessors of the Building, or any portion thereof. Notwithstanding the
foregoing provisions of this Section 10.2, the coverage and amounts of insurance
carried by Landlord in connection with the Building shall at a minimum be
comparable to the coverage and amounts of insurance which are carried by
reasonably prudent landlords of Buildings comparable to the Building in the
vicinity of the Building. Tenant shall, at Tenant's expense, comply with all
insurance company requirements pertaining to the use of the Premises. If
Tenant's conduct or use of the Premises causes any increase in the premium for
such insurance policies then Tenant shall reimburse Landlord for any such
increase.

        10.3 TENANT'S INSURANCE. Tenant shall maintain the following coverages
in the following amounts.

                10.3.1 Commercial General Liability Insurance covering the
insured against claims of bodily injury, personal injury and property damage
(including loss of use thereof) arising out of Tenant's operations, actions, and
contractual liabilities (covering the performance by Tenant of its indemnity
agreements) including a Broad Form endorsement covering the insuring provisions
of this Lease and the performance by Tenant of the indemnity agreements set
forth in Section 10.1 of this Lease, for limits of liability (with a
commercially reasonable deductible) not less than:

<TABLE>
   <S>                                        <C>
   Bodily Injury and                          $2,000,000 each occurrence
   Property Damage Liability                  $2,000,000 annual aggregate

   Personal Injury Liability                  $2,000,000 each occurrence
                                              $2,000,000 annual aggregate
</TABLE>

                10.3.2 All Risk Property Insurance covering (i) all office
furniture, business and trade fixtures, office equipment, free-standing cabinet
work, movable partitions, merchandise and all other items of Tenant's property
on the Premises installed by, for, or at the expense of Tenant, (ii) the

                                      -23-
<PAGE>   30

"Tenant Improvements", as that term is defined in Section 2.1 of the Tenant Work
Letter and any other improvements which exist in the Premises as of the Lease
Commencement Date (excluding the Base Building) (the "ORIGINAL IMPROVEMENTS"),
(iii) the Tenant's business interruption and extra expense in an amount equal to
one (1) year of Rent due under this Lease and (iv) all other improvements,
alterations and additions to the Premises. Such insurance shall be written on an
"all risks" of physical loss or damage basis, for the full replacement cost
value (subject to reasonable deductible amounts) and with an agreed amount
endorsement, and shall include coverage for damage or other loss caused by fire
or other peril including, but not limited to, vandalism and malicious mischief,
theft, water damage of any type, including sprinkler leakage, earthquake
sprinkler leakage, bursting or stoppage of pipes, and explosion.

                10.3.3 Worker's Compensation and Employer's Liability in an
amount no less than $1,000,000.00 or other similar insurance pursuant to all
applicable state and local statutes and regulations.

                10.3.4 Prior to commencing construction in the Premises in
connection with any Alterations, Tenant shall provide Landlord with evidence
that any contractors, subcontractors, architects or engineers engaged by Tenant
for construction in the Premises carry insurance of the type and in the amount
required to be carried by Tenant pursuant to Sections 10.3.1 and 10.3.2, above,
or such lesser amount as approved by Landlord, which approval shall not be
unreasonably withheld. In addition, unless otherwise approved in advance by the
Owner, which approval shall not be unreasonably withheld or delayed, any general
contractor's policy of insurance shall contain an owner's contractor protective
endorsement, and coverage for work performed by others, and any contractors or
subcontractors insurance shall contain products and completed operations
coverage and said contractor shall warrant that it shall continue to carry such
coverage for a period of not less than ten (10) years. Any architects or
engineers engaged by Tenant in connection with any such construction shall
additionally carry errors and omissions insurance coverage. In addition,
Landlord may, in its discretion, require that Tenant obtain a lien and
completion bond or some alternate form of security satisfactory to Landlord in
an amount sufficient to ensure the lien-free completion of such Alterations and
naming Landlord as a co-obligee for those Alterations involving One Hundred
Thousand Dollars ($100,000.00) or more of work.

        10.4 FORM OF POLICIES. The minimum limits of policies of insurance
required of Tenant or its contractors, subcontractors, architects or engineers
under this Lease shall in no event limit the liability of Tenant under this
Lease. Such insurance shall (i) as appropriate name Landlord, and any other
party the Landlord so specifies, as an additional insured, including Landlord's
managing agent, if any; (ii) specifically cover the liability assumed by Tenant
under this Lease, including, but not limited to, Tenant's obligations under
Section 10.1 of this Lease; (iii) be issued by an insurance company having a
rating of not less than A-X in Best's Insurance Guide or which is otherwise
acceptable to Landlord and licensed to do business in the State of California;
(iv) be primary insurance as to all claims thereunder and provide that any
insurance carried by Landlord is excess and is non-contributing with any
insurance requirement of Tenant; (v) be in form and content reasonably
acceptable to Landlord; and (vi) provide that said insurance shall not be
canceled or coverage materially changed unless thirty (30) days' prior written
notice shall have been given to

                                      -24-
<PAGE>   31

Landlord and any mortgagee of Landlord by the insurer or the Tenant. Tenant
shall deliver said policy or policies or certificates thereof to Landlord on or
before the Lease Commencement Date and at least thirty (30) days before the
expiration dates thereof. In the event Tenant shall fail to procure such
insurance, or to deliver such policies or certificate, Landlord may, at its
option, procure such policies for the account of Tenant, and the cost thereof
shall be paid to Landlord within five (5) days after delivery to Tenant of bills
therefor.

        10.5 SUBROGATION. Notwithstanding anything to the contrary contained in
this Lease, Landlord and Tenant intend that their respective property loss risks
shall be borne by reasonable insurance carriers to the extent above provided,
and Landlord and Tenant hereby agree to look solely to, and seek recovery only
from, their respective insurance carriers in the event of a property loss which
is caused by or results from a risk which in actually insured against, which is
required to be insured against under this Lease, or which would normally be
covered by "all risk" property insurance, without regard to the negligence or
willful misconduct of the person or entity to be released. The parties each
hereby waive all rights and claims against each other for such losses, and waive
all rights of subrogation of their respective insurers, provided such waiver of
subrogation shall not affect the right to the insured to recover thereunder. The
parties agree that their respective insurance policies are now, or shall be,
endorsed such that the waiver of subrogation shall not affect the right of the
insured to recover thereunder.

        10.6 ADDITIONAL INSURANCE OBLIGATIONS. Tenant shall carry and maintain
during any Option Term, at Tenant's sole cost and expense, increased amounts of
the insurance required to be carried by Tenant pursuant to this Article 10 and
such other reasonable types of insurance coverage and in such reasonable amounts
covering the Premises and Tenant's operations therein, as may be reasonably
requested by Landlord.

                                   ARTICLE 11

                             DAMAGE AND DESTRUCTION

        11.1 REPAIR OF DAMAGE TO PREMISES BY LANDLORD. Tenant shall promptly
notify Landlord of any damage to the Premises resulting from fire or any other
loss. If the Premises or any Common Areas serving or providing access to the
Premises shall be damaged by fire or other casualty, Landlord shall (i) provide
a written notice to Tenant indicating the anticipated period for repairing the
damage (the "REPAIR PERIOD NOTICE"), and (ii) promptly and diligently, subject
to reasonable delays for insurance adjustment or other matters beyond Landlord's
reasonable control, and subject to all other terms of this Article 11, restore
the Base Building and such Common Areas. Such restoration shall be to
substantially the same condition of the Base Building and the Common Areas prior
to the casualty, except for modifications required by zoning and building codes
and other laws or by the holder of a mortgage on the Building or Project or any
other modifications to the Common Areas reasonably deemed desirable by Landlord,
provided that access to the Premises and any common restrooms serving the
Premises shall not be materially impaired. Upon the occurrence of any damage to
the Premises, Tenant shall assign to Landlord (or to any party designated by
Landlord) all insurance proceeds payable to Tenant under Tenant's insurance
required under

                                      -25-
<PAGE>   32

Section 10.3 of this Lease, and Landlord shall repair any injury or damage to
the Tenant Improvements and the Original Improvements installed in the Premises
and shall return such Tenant Improvements and Original Improvements to their
original condition; provided that if the cost of such repair by Landlord exceeds
the amount of insurance proceeds received by Landlord from Tenant's insurance
carrier, as assigned by Tenant, the cost of such repairs shall be paid by Tenant
to Landlord prior to Landlord's commencement of repair of the damage. Landlord
shall not be liable for any inconvenience or annoyance to Tenant or its
visitors, or injury to Tenant's business resulting in any way from such damage
or the repair thereof; provided however, that if such fire or other casualty
shall have damaged the Premises or Common Areas necessary to Tenant's occupancy,
Landlord shall allow Tenant a proportionate abatement of Rent, during the time
and to the extent the Premises are unfit for occupancy for the purposes
permitted under this Lease, and not occupied by Tenant as a result thereof.

        11.2 LANDLORD'S OPTION TO REPAIR. Notwithstanding the terms of Section
11.1 of this Lease, Landlord may elect not to rebuild and/or restore the
Premises, Building and/or Project, and instead terminate this Lease, by
notifying Tenant in writing of such termination no later than sixty (60) days
after the date of the discovery of damage (and Landlord will use reasonable
efforts to notify Tenant sooner), such notice to include a termination date
giving Tenant sixty (60) days to vacate the Premises, but Landlord may so elect
only if the Building or Project shall be damaged by fire or other casualty or
cause, whether or not the Premises are affected, Landlord's election to
terminate the leases of other similarly situated tenants in the Building or
Project is exercised in a non-discriminatory manner, and one or more of the
following conditions is present: (i) in Landlord's reasonable judgment, repairs
cannot reasonably be completed within one hundred eighty (180) days (or in the
event of damage resulting from earthquake, three hundred sixty (360) days) after
the date of damage (when such repairs are made without the payment of overtime
or other premiums); (ii) the holder of any mortgage on the Building or Project
or ground lessor with respect to the Building or Project shall require that the
insurance proceeds or any portion thereof be used to retire the mortgage debt,
or shall terminate the ground lease, as the case may be; (iii) the damage is not
fully covered by Landlord's insurance policies and the uninsured portion of such
repairs amounts to Two Hundred Thousand Dollars ($200,000.00) or more; or (iv)
the damage occurs during the last twelve (12) months of the Lease Term.

        11.3 WAIVER OF STATUTORY PROVISIONS. The provisions of this Lease,
including this Article 11, constitute an express agreement between Landlord and
Tenant with respect to any and all damage to, or destruction of, all or any part
of the Premises, the Building or the Project, and any statute or regulation of
the State of California, including, without limitation, Sections 1932(2) and
1933(4) of the California Civil Code, with respect to any rights or obligations
concerning damage or destruction in the absence of an express agreement between
the parties, and any other statute or regulation, now or hereafter in effect,
shall have no application to this Lease or any damage or destruction to all or
any part of the Premises, the Building or the Project.

        11.4 TENANT'S OPTION(s) TO TERMINATE. If (i) the Repair Period Notice
provided by Landlord indicates that the anticipated period for repairing the
damage exceeds one hundred eighty (180) days, or (ii) the Building is destroyed
or damaged during the last twelve (12) months of the

                                      -26-
<PAGE>   33

Lease Term, and (iii) Landlord has not elected to terminate the Lease pursuant
to Section 11.2 above, Tenant shall have the option to terminate this Lease by
giving written notice to Landlord of the exercise of that option within sixty
(60) days after damage or destruction occurs. If Tenant does not elect to
terminate within this sixty (60) day period, Tenant shall be considered to have
waived the option to terminate.

                                   ARTICLE 12

                                    NONWAIVER

        No provision of this Lease shall be deemed waived by either party hereto
unless expressly waived in a writing signed thereby. The waiver by either party
hereto of any breach of any term, covenant or condition herein contained shall
not be deemed to be a waiver of any subsequent breach of same or any other term,
covenant or condition herein contained. The subsequent acceptance of Rent
hereunder by Landlord shall not be deemed to be a waiver of any preceding breach
by Tenant of any term, covenant or condition of this Lease, other than the
failure of Tenant to pay the particular Rent so accepted, regardless of
Landlord's knowledge of such preceding breach at the time of acceptance of such
Rent. No acceptance of a lesser amount than the Rent herein stipulated shall be
deemed a waiver of Landlord's right to receive the full amount due, nor shall
any endorsement or statement on any check or payment or any letter accompanying
such check or payment be deemed an accord and satisfaction, and Landlord may
accept such check or payment without prejudice to Landlord's right to recover
the full amount due. No receipt of monies by Landlord from Tenant after the
termination of this Lease shall in any way alter the length of the Lease Term or
of Tenant's right of possession hereunder, or after the giving of any notice
shall reinstate, continue or extend the Lease Term or affect any notice given
Tenant prior to the receipt of such monies, it being agreed that after the
service of notice or the commencement of a suit, or after final judgment for
possession of the Premises, Landlord may receive and collect any Rent due, and
the payment of said Rent shall not waive or affect said notice, suit or
judgment.

                                   ARTICLE 13

                                  CONDEMNATION

        If the whole or any part thereof necessary for the reasonable use of the
Premises, Building or Project shall be taken by power of eminent domain or
condemned by any competent authority for any public or quasi-public use or
purpose, or if any adjacent property or street shall be so taken or condemned,
or reconfigured or vacated by such authority in such manner as to require the
use, reconstruction or remodeling of a substantial part of the Premises,
Building or Project, or if Landlord shall grant a deed or other instrument in
lieu of such taking by eminent domain or condemnation, Landlord shall have the
option to terminate this Lease effective as of the date possession is required
to be surrendered to the authority. If more than twenty-five percent (25%) of
the rentable square feet of the Premises is taken, or if access to the Premises
is substantially impaired, in each case for a period in excess of one hundred
eighty (180) days, Tenant shall have the option to terminate this Lease
effective as of the date possession is required to be surrendered to the
authority. Tenant shall

                                      -27-
<PAGE>   34

not because of such taking assert any claim against Landlord or the authority
for any compensation because of such taking and Landlord shall be entitled to
the entire award or payment in connection therewith, except that Tenant shall
have the right to file any separate claim available to Tenant for any taking of
Tenant's personal property and fixtures belonging to Tenant and removable by
Tenant upon expiration of the Lease Term pursuant to the terms of this Lease,
and for moving expenses, so long as such claims do not diminish the award
available to Landlord, its ground lessor with respect to the Building or Project
or its mortgagee, and such claim is payable separately to Tenant. All Rent shall
be apportioned as of the date of such termination. If any part of the Premises
shall be taken, and this Lease shall not be so terminated, the Rent shall be
proportionately abated. Tenant hereby waives any and all rights it might
otherwise have pursuant to Section 1265.130 of The California Code of Civil
Procedure. Notwithstanding anything to the contrary contained in this Article
13, in the event of a temporary taking of all or any portion of the Premises for
a period of one hundred and eighty (180) days or less, then this Lease shall not
terminate but the Base Rent and the Additional Rent shall be abated for the
period of such taking in proportion to the ratio that the amount of rentable
square feet of the Premises taken bears to the total rentable square feet of the
Premises. Landlord shall be entitled to receive the entire award made in
connection with any such temporary taking.

                                   ARTICLE 14

                            ASSIGNMENT AND SUBLETTING

        14.1 TRANSFERS. Tenant shall not, without the prior written consent of
Landlord, assign, mortgage, pledge, hypothecate, encumber, or permit any lien to
attach to, or otherwise transfer, this Lease or any interest hereunder, permit
any assignment, or other transfer of this Lease or any interest hereunder by
operation of law, sublet the Premises or any part thereof, or enter into any
license or concession agreements or otherwise permit the occupancy or use of the
Premises or any part thereof by any persons other than Tenant and its employees
and contractors (all of the foregoing are hereinafter sometimes referred to
collectively as "TRANSFERS" and any person to whom any Transfer is made or
sought to be made is hereinafter sometimes referred to as a "TRANSFEREE"). If
Tenant desires Landlord's consent to any Transfer, Tenant shall notify Landlord
in writing, which notice (the "TRANSFER NOTICE") shall include (i) the proposed
effective date of the Transfer, which shall not be less than thirty (30) days
nor more than one hundred eighty (180) days after the date of delivery of the
Transfer Notice, (ii) a description of the portion of the Premises to be
transferred (the "SUBJECT SPACE"), (iii) all of the terms of the proposed
Transfer and the consideration therefor, including calculation of the "Transfer
Premium", as that term is defined in Section 14.3 below, in connection with such
Transfer, the name and address of the proposed Transferee, and a copy of all
existing executed and/or proposed documentation pertaining to the proposed
Transfer, including all existing operative documents to be executed to evidence
such Transfer or the agreements incidental or related to such Transfer and (iv)
financial statements for the prior two (2) fiscal years of the proposed
Transferee certified by an officer, partner or owner thereof, business credit
and personal references and history of the proposed Transferee and any other
information required by Landlord which will enable Landlord to determine the
financial responsibility, character, and reputation of the proposed Transferee,
nature of such Transferee's business and proposed use of the Subject Space.

                                      -28-
<PAGE>   35

Any Transfer made without Landlord's prior written consent shall, at Landlord's
option, be null, void and of no effect, and shall, at Landlord's option,
constitute a default by Tenant under this Lease. Whether or not Landlord
consents to any proposed Transfer, Tenant shall pay Landlord's review and
processing fees, as well as any reasonable professional fees (including, without
limitation, attorneys', accountants', architect's, engineers' and consultants'
fees) incurred by Landlord, not to exceed One Thousand and 00/100 Dollars
($1,000.00) for a Transfer in the ordinary course of business, within thirty
(30) days after written request by Landlord.

        14.2 LANDLORD'S CONSENT. Landlord shall not unreasonably withhold its
consent to any proposed Transfer of the Subject Space to the Transferee on the
terms specified in the Transfer Notice. Without limitation as to other
reasonable grounds for withholding consent, the parties hereby agree that it
shall be reasonable under this Lease and under any applicable law for Landlord
to withhold consent to any proposed Transfer where one or more of the following
apply:

                14.2.1 The Transferee is of a character or reputation or engaged
in a business which is not consistent with the quality of the Building or the
Project, or would be a significantly less prestigious occupant of the Building
than Tenant;

                14.2.2 The Transferee intends to use the Subject Space for
purposes which are not permitted under this Lease;

                14.2.3 The Transferee is either a governmental agency or
instrumentality thereof;

                14.2.4 The Transferee is not a party of reasonable financial
worth and/or financial stability in light of the responsibilities to be
undertaken in connection with the Transfer;

                14.2.5 The proposed Transfer would cause a violation of another
lease for space in the Project, or would give an occupant of the Project a right
to cancel its lease;

                14.2.6 The terms of the proposed Transfer will allow a
Transferee other than an Affiliate to exercise a right of renewal, right of
expansion, right of first offer, or other similar right held by Tenant (or will
allow the Transferee to occupy space leased by Tenant pursuant to any such
right); or

                14.2.7 Either the proposed Transferee, or any person or entity
which directly or indirectly, controls, is controlled by, or is under common
control with, the proposed Transferee, (i) occupies space in the Project at the
time of the request for consent, or (ii) is negotiating or has actively
negotiated with Landlord in the one hundred twenty (120) day period prior to the
date of the Transfer Notice to lease space in the Project.

        If Landlord consents to any Transfer pursuant to the terms of this
Section 14.2 (and does not exercise any recapture rights Landlord may have under
Section 14.4 of this Lease), Tenant may within six (6) months after Landlord's
consent, but not later than the expiration of said six-month period, enter into
such Transfer of the Premises or portion thereof, upon substantially the same
terms and conditions as are set forth in the Transfer Notice furnished by Tenant
to Landlord pursuant to

                                      -29-
<PAGE>   36

Section 14.1 of this Lease, provided that if there are any changes in the terms
and conditions from those specified in the Transfer Notice (i) such that
Landlord would initially have been entitled to refuse its consent to such
Transfer under this Section 14.2, or (ii) which would cause the proposed
Transfer to be more favorable to the Transferee than the terms set forth in
Tenant's original Transfer Notice, Tenant shall again submit the Transfer to
Landlord for its approval and other action under this Article 14 (including
Landlord's right of recapture, if any, under Section 14.4 of this Lease).
Notwithstanding anything to the contrary in this Lease, if Tenant or any
proposed Transferee claims that Landlord has unreasonably withheld or delayed
its consent under Section 14.2 or otherwise has breached or acted unreasonably
under this Article 14, their sole remedies shall be a declaratory judgment and
an injunction for the relief sought together with any monetary damages, provided
that Tenant hereby waives all other remedies, including, without limitation, any
right at law or equity to terminate this Lease, on its own behalf and, to the
extent permitted under all applicable laws, on behalf of the proposed
Transferee.

        14.3 TRANSFER PREMIUM. If Landlord consents to a Transfer, as a
condition thereto which the parties hereby agree is reasonable, Tenant shall pay
to Landlord fifty percent (50%) of any "Transfer Premium," as that term is
defined in this Section 14.3, received by Tenant from such Transferee. "TRANSFER
PREMIUM" shall mean all rent, additional rent or other consideration payable by
such Transferee in connection with the Transfer in excess of the Rent and
Additional Rent payable by Tenant under this Lease during the term of the
Transfer on a per rentable square foot basis if less than all of the Premises is
transferred, after deducting the reasonable expenses incurred by Tenant for (i)
any changes, alterations and improvements to the Premises in connection with the
Transfer, (ii) any free base rent reasonably provided to the Transferee, and
(iii) any brokerage commissions, and (iv) reasonable attorneys' fees in
connection with the Transfer (collectively, "TENANT'S SUBLEASING COSTS").
"Transfer Premium" shall also include, but not be limited to, key money, bonus
money or other cash consideration paid by Transferee to Tenant as consideration
for such Transfer and which consideration is in excess of fair market value for
services rendered by Tenant to Transferee or for assets, fixtures, inventory,
equipment, or furniture transferred by Tenant to Transferee in connection with
such Transfer. The determination of the amount of Landlord's applicable share of
the Transfer Premium shall be made on a monthly basis as rent or other
consideration is received by Tenant under the Transfer. For purposes of
calculating the Transfer Premium on a monthly basis, (i) Tenant's Subleasing
Costs shall be deemed to be expended by Tenant in equal monthly amounts over the
entire term of the Transfer and (ii) the Rent paid for the Subject Space by
Tenant shall be computed after adjusting such rent to the actual effective rent
to be paid, taking into consideration any and all leasehold concessions granted
in connection therewith, including, but not limited to, any rent credit and
tenant improvement allowance. For purposes of calculating any such effective
rent all such concessions shall be amortized on a straight-line basis over the
relevant term.

        14.4 LANDLORD'S OPTION AS TO SUBJECT SPACE. Notwithstanding anything to
the contrary contained in this Article 14, Landlord shall have the option, by
giving written notice to Tenant within thirty (30) days after receipt of any
Transfer Notice, to recapture the Subject Space. Such recapture notice shall
cancel and terminate this Lease with respect to the Subject Space as of the date
stated in the Transfer Notice as the effective date of the proposed Transfer
until the last day of the

                                      -30-
<PAGE>   37

term of the Transfer as set forth in the Transfer Notice (or at Landlord's
option, shall cause the Transfer to be made to Landlord or its agent, in which
case the parties shall execute the Transfer documentation promptly thereafter).
In the event of a recapture by Landlord, if this Lease shall be canceled with
respect to less than the entire Premises, the Rent reserved herein shall be
prorated on the basis of the number of rentable square feet retained by Tenant
in proportion to the number of rentable square feet contained in the Premises,
and this Lease as so amended shall continue thereafter in full force and effect,
and upon request of either party, the parties shall execute written confirmation
of the same. If Landlord declines, or fails to elect in a timely manner to
recapture the Subject Space under this Section 14.4, then, provided Landlord has
consented to the proposed Transfer, Tenant shall be entitled to proceed to
transfer the Subject Space to the proposed Transferee, subject to provisions of
this Article 14.

        14.5 EFFECT OF TRANSFER. If Landlord consents to a Transfer, (i) the
terms and conditions of this Lease shall in no way be deemed to have been waived
or modified, (ii) such consent shall not be deemed consent to any further
Transfer by either Tenant or a Transferee, (iii) Tenant shall deliver to
Landlord, promptly after execution, an original executed copy of all
documentation pertaining to the Transfer in form reasonably acceptable to
Landlord, (iv) Tenant shall furnish upon Landlord's request a complete
statement, certified by an independent certified public accountant, or Tenant's
chief financial officer, setting forth in detail the computation of any Transfer
Premium Tenant has derived and shall derive from such Transfer, and (v) no
Transfer relating to this Lease or agreement entered into with respect thereto,
whether with or without Landlord's consent, shall relieve Tenant or any
guarantor of the Lease from any liability under this Lease, including, without
limitation, in connection with the Subject Space. Landlord or its authorized
representatives shall have the right at all reasonable times to audit the books,
records and papers of Tenant relating to any Transfer, and shall have the right
to make copies thereof. If the Transfer Premium respecting any Transfer shall be
found understated, Tenant shall, within thirty (30) days after demand, pay the
deficiency, and if understated by more than two percent (2%), Tenant shall pay
Landlord's costs of such audit.

        14.6 ADDITIONAL TRANSFERS. Except as otherwise set forth in Section
14.8, for purposes of this Lease, the term "TRANSFER" shall also include (i) if
Tenant is a partnership, the withdrawal or change, voluntary, involuntary or by
operation of law, of fifty percent (50%) or more of the partners, or transfer of
fifty percent (50%) or more of partnership interests, within a twelve (12)-month
period, or the dissolution of the partnership without immediate reconstitution
thereof, and (ii) if Tenant is a closely held corporation (i.e., whose stock is
not publicly held and not traded through an exchange or over the counter), (A)
the dissolution, merger, consolidation or other reorganization of Tenant or (B)
the sale or other transfer of an aggregate of fifty percent (50%) or more of the
voting shares of Tenant (other than to immediate family members by reason of
gift or death), within a twelve (12)-month period, or (C) the sale, mortgage,
hypothecation or pledge of an aggregate of fifty percent (50%) or more of the
value of the unencumbered assets of Tenant within a twelve (12)-month period.

        14.7 OCCURRENCE OF DEFAULT. Any Transfer hereunder shall be subordinate
and subject to the provisions of this Lease, and if this Lease shall be
terminated during the term of any Transfer, Landlord shall have the right to:
(i) treat such Transfer as cancelled and repossess the Subject Space

                                      -31-
<PAGE>   38

by any lawful means, or (ii) require that such Transferee attorn to and
recognize Landlord as its landlord under any such Transfer. Upon any assignment,
the assignee shall assume in writing all obligations and covenants of Tenant
thereafter to be performed or observed under this Lease. No collection or
acceptance of rent by Landlord from any Transferee shall be deemed a waiver of
any provision of this Article 14 or the approval of any Transferee or a release
of Tenant from any obligation under this Lease, whether theretofore or
thereafter accruing. In no event shall Landlord's enforcement of any provision
of this Lease against any Transferee be deemed a waiver of Landlord's right to
enforce any term of this Lease against Tenant or any other person. If Tenant's
obligations hereunder have been guaranteed, Landlord's consent to any Transfer
shall not be effective unless the guarantor also consents to such Transfer.

        14.8 NON-TRANSFERS. Notwithstanding anything to the contrary contained
in Article 14 of this Lease, an assignment or subletting of all or a portion of
the Premises (i) to an affiliate of Tenant (an entity which is controlled by,
controls, or is under common control with, Tenant), (ii) to a successor
corporation resulting from the merger or consolidation of Tenant with another
entity, or (iii) to an entity that purchases all of the assets of the distinct
business unit of Tenant operating in the Premises, which entity has an equal or
greater net worth to Tenant immediately following such purchase (collectively,
"Affiliates") shall not be deemed a Transfer under Article 14 of this Lease,
provided that Tenant notifies Landlord of any such assignment or sublease and
promptly supplies Landlord with any documents or information requested by
Landlord regarding such assignment or sublease or such Affiliates, and further
provided that such assignment or sublease is not a subterfuge by Tenant to avoid
its obligations under this Lease. "Control," as used in this Section 14.8, shall
mean the ownership, directly or indirectly, of at least fifty-one percent (51%)
of the voting securities of, or possession of the right to vote, in the ordinary
direction of its affairs, of at least fifty-one percent (51%) of the voting
interest in, an person or entity.

                                   ARTICLE 15

                      SURRENDER OF PREMISES; OWNERSHIP AND
                            REMOVAL OF TRADE FIXTURES

        15.1 SURRENDER OF PREMISES. No act or thing done by Landlord or any
agent or employee of Landlord during the Lease Term shall be deemed to
constitute an acceptance by Landlord of a surrender of the Premises unless such
intent is specifically acknowledged in writing by Landlord. The delivery of keys
to the Premises to Landlord or any agent or employee of Landlord shall not
constitute a surrender of the Premises or effect a termination of this Lease,
whether or not the keys are thereafter retained by Landlord, and notwithstanding
such delivery Tenant shall be entitled to the return of such keys at any
reasonable time upon request until this Lease shall have been properly
terminated. The voluntary or other surrender of this Lease by Tenant, whether
accepted by Landlord or not, or a mutual termination hereof, shall not work a
merger, and at the option of Landlord shall operate as an assignment to Landlord
of all subleases or subtenancies affecting the Premises or terminate any or all
such sublessees or subtenancies.

                                      -32-
<PAGE>   39

        15.2 REMOVAL OF TENANT PROPERTY BY TENANT. Upon the expiration of the
Lease Term, or upon any earlier termination of this Lease, Tenant shall, subject
to the provisions of this Article 15, quit and surrender possession of the
Premises to Landlord in the condition existing as of the Lease Commencement
Date, reasonable wear and tear, casualty, condemnation, Hazardous Materials not
brought onto the Premises by the Tenant Parties, and repairs, which are
specifically made the responsibility of Landlord hereunder, and any Alterations
which Tenant is not required to remove at the termination of this Lease pursuant
to Section 8.2 above, excepted. Upon such expiration or termination, Tenant
shall, without expense to Landlord, remove or cause to be removed from the
Premises all debris and rubbish, and such items of furniture, equipment,
business and trade fixtures, free-standing cabinet work, movable partitions and
other articles of personal property owned by Tenant or installed or placed by
Tenant at its expense in the Premises, and such similar articles of any other
persons claiming under Tenant, as Landlord, in its reasonable discretion,
require Tenant to remove at the time of installation, and Tenant shall repair at
its own expense all damage to the Premises and Building resulting from such
removal.

                                   ARTICLE 16

                                  HOLDING OVER

        If Tenant holds over after the expiration of the Lease Term or earlier
termination thereof, with or without the express or implied consent of Landlord,
such tenancy shall be from month-to-month only, and shall not constitute a
renewal hereof or an extension for any further term, and in such case Rent shall
be payable at a monthly rate equal to one hundred fifty percent (150%) of the
Rent applicable during the last rental period of the Lease Term under this
Lease. Such month-to-month tenancy shall be subject to every other applicable
term, covenant and agreement contained herein. Nothing contained in this Article
16 shall be construed as consent by Landlord to any holding over by Tenant, and
Landlord expressly reserves the right to require Tenant to surrender possession
of the Premises to Landlord as provided in this Lease upon the expiration or
other termination of this Lease. The provisions of this Article 16 shall not be
deemed to limit or constitute a waiver of any other rights or remedies of
Landlord provided herein or at law. If Tenant fails to surrender the Premises
upon the termination or expiration of this Lease, in addition to any other
liabilities to Landlord accruing therefrom, Tenant shall protect, defend,
indemnify and hold Landlord harmless from all loss, costs (including reasonable
attorneys' fees) and liability resulting from such failure, including, without
limiting the generality of the foregoing, any claims made by any succeeding
tenant founded upon such failure to surrender and any lost profits to Landlord
resulting therefrom.

                                   ARTICLE 17

                              ESTOPPEL CERTIFICATES

        Within ten (10) business days following a request in writing by
Landlord, Tenant shall execute, acknowledge and deliver to Landlord an estoppel
certificate, which, as submitted by Landlord, shall be substantially in the form
of EXHIBIT E, attached hereto (or such other form as may

                                      -33-
<PAGE>   40

be required by any prospective mortgagee or purchaser of the Project, or any
portion thereof, indicating therein any exceptions thereto that may exist at
that time, and shall also contain any other information reasonably requested by
Landlord or Landlord's mortgagee or prospective mortgagee. Any such certificate
may be relied upon by any prospective mortgagee or purchaser of all or any
portion of the Project. Tenant shall execute and deliver whatever other
instruments may be reasonably required for such purposes within ten (10)
business days after receipt of a request by Landlord. At any time during the
Lease Term, but in no event more than once during each Lease Year, Landlord may
require Tenant to provide Landlord within ten (10) business days after receipt
of a request by Landlord with a current financial statement and financial
statements of the two (2) years prior to the current financial statement year.
Such statements shall be prepared in accordance with generally accepted
accounting principles and, if such is the normal practice of Tenant, shall be
audited by an independent certified public accountant. Failure of Tenant to
timely execute, acknowledge and deliver such estoppel certificate or other
instruments shall constitute an acceptance of the Premises and an acknowledgment
by Tenant that statements included in the estoppel certificate are true and
correct, without exception.

                                   ARTICLE 18

                                  SUBORDINATION

        Landlord represents to Tenant that there are no current mortgages or
deeds of trust encumbering the Building or Project. This Lease shall be subject
and subordinate to all present and future ground or underlying leases of the
Building or Project and to the lien of any mortgage, trust deed or other
encumbrances hereafter in force against the Building or Project or any part
thereof, if any, and to all renewals, extensions, modifications, consolidations
and replacements thereof, and to all advances made or hereafter to be made upon
the security of such mortgages or trust deeds, unless the holders of such
mortgages, trust deeds or other encumbrances, or the lessors under such ground
lease or underlying leases (collectively, "MORTGAGEES"), require in writing that
this Lease be superior thereto. In consideration of, and as a condition
precedent to, Tenant's agreement to permit its interest pursuant to this Lease
to be subordinated to any particular future ground or underlying lease of the
Building or the Project or to the lien of any first mortgage or trust deed,
hereafter enforced against the Building or the Project and to any renewals,
extensions, modifications, consolidations and replacements thereof, Landlord
shall deliver to Tenant a commercially reasonable non-disturbance agreement (the
"SNDA") executed by the landlord under such ground lease or underlying lease or
the holder of such mortgage or trust deed, as appropriate, recognizing this
Lease, any successor Landlord's obligation to perform hereunder, and Tenant's
right to offset Rent pursuant to the terms of this Lease. Tenant covenants and
agrees in the event any proceedings are brought for the foreclosure of any such
mortgage or deed in lieu thereof (or if any ground lease is terminated), to
attorn subject to the terms of the SNDA, without any deductions or set-offs
whatsoever, to the lienholder or purchaser or any successors thereto upon any
such foreclosure sale or deed in lieu thereof (or to the ground lessor), so by
such purchaser or lienholder or ground lessor, and to recognize such purchaser
or lienholder or ground lessor as the lessor under this Lease, provided that,
subject to the terms of the SNDA, such lienholder or purchaser or ground lessor
shall agree to accept this Lease, perform Landlord's obligations, recognize
Tenant's rights and obligations, and not to

                                      -34-
<PAGE>   41

disturb Tenant's occupancy, so long as Tenant timely pays the rent and observes
and performs the terms, covenants and conditions of this Lease to be observed
and performed by Tenant. Landlord's interest herein may be assigned as security
at any time to any lienholder. Tenant shall, within ten (10) days of request by
Landlord, execute such further instruments or assurances as Landlord may
reasonably deem necessary to evidence or confirm the subordination or
superiority of this Lease to any such mortgages, trust deeds, ground leases or
underlying leases. Tenant waives the provisions of any current or future
statute, rule or law which may give or purport to give Tenant any right or
election to terminate or otherwise adversely affect this Lease and the
obligations of the Tenant hereunder in the event of any foreclosure proceeding
or sale.

                                   ARTICLE 19

                               DEFAULTS; REMEDIES

        19.1 EVENTS OF DEFAULT. The occurrence of any of the following shall
constitute a default of this Lease by Tenant:

                19.1.1 Any failure by Tenant to pay any Rent or any other charge
required to be paid under this Lease, or any part thereof, when due unless such
failure is cured within five (5) days after notice; or

                19.1.2 Any failure by Tenant to observe or perform any other
provision, covenant or condition of this Lease to be observed or performed by
Tenant where such failure continues for ten (10) days after written notice
thereof from Landlord to Tenant; provided that if the nature of such default is
such that the same cannot reasonably be cured within a ten (10) day period,
Tenant shall not be deemed to be in default if it diligently commences such cure
within such period and thereafter diligently proceeds to rectify and cure such
default; or

                19.1.3 Abandonment of all or any portion of the Premises by
Tenant; or

                19.1.4 The failure by Tenant to observe or perform according to
the provisions of Articles 5, 14, 17 or 18 of this Lease where such failure
continues for more than five (5) business days after notice from Landlord.

        The notice periods provided herein are in lieu of, and not in addition
to, any notice periods provided by law.

        19.2 REMEDIES UPON DEFAULT. Upon the occurrence of any event of default
by Tenant, Landlord shall have, in addition to any other remedies available to
Landlord at law or in equity (all of which remedies shall be distinct, separate
and cumulative), the option to pursue any one or more of the following remedies,
each and all of which shall be cumulative and nonexclusive, without any notice
or demand whatsoever.

                19.2.1 Terminate this Lease, in which event Tenant shall
immediately surrender the Premises to Landlord, and if Tenant fails to do so,
Landlord may, without prejudice to any other

                                      -35-
<PAGE>   42

remedy which it may have for possession or arrearages in rent, enter upon and
take possession of the Premises and expel or remove Tenant and any other person
who may be occupying the Premises or any part thereof, without being liable for
prosecution or any claim or damages therefor; and Landlord may recover from
Tenant the following:

                (i) The worth at the time of any unpaid rent which has been
earned at the time of such termination; plus

                (ii) The worth at the time of award of the amount by which the
unpaid rent which would have been earned after termination until the time of
award exceeds the amount of such rental loss that Tenant proves could have been
reasonably avoided; plus

                (iii) The worth at the time of award of the amount by which the
unpaid rent for the balance of the Lease Term after the time of award exceeds
the amount of such rental loss that Tenant proves could have been reasonably
avoided; plus

                (iv) Any other amount necessary to compensate Landlord for all
the detriment proximately caused by Tenant's failure to perform its obligations
under this Lease or which in the ordinary course of things would be likely to
result therefrom, specifically including but not limited to, brokerage
commissions and advertising expenses incurred, expenses of remodeling the
Premises or any portion thereof for a new tenant, whether for the same or a
different use, and any special concessions made to obtain a new tenant; and

                (v) At Landlord's election, such other amounts in addition to or
in lieu of the foregoing as may be permitted from time to time by applicable
law.

        The term "rent" as used in this Section 19.2 shall be deemed to be and
to mean all sums of every nature required to be paid by Tenant pursuant to the
terms of this Lease, whether to Landlord or to others. As used in Sections
19.2.1(i) and (ii), above, the "worth at the time of award" shall be computed by
allowing interest at the rate set forth in Article 25 of this Lease, but in no
case greater than the maximum amount of such interest permitted by law. As used
in Section 19.2.1(iii) above, the "worth at the time of award" shall be computed
by discounting such amount at the discount rate of the Federal Reserve Bank of
San Francisco at the time of award plus one percent (1%). If Landlord terminates
this Lease or Tenant's right to possession, Landlord shall use reasonable
efforts to mitigate Landlord's damages, and Tenant shall be entitled to submit
proof of such failure to mitigate as a defense to Landlord's claims hereunder,
if mitigation of damages by Landlord is required by applicable law.

                19.2.2 Landlord shall have the remedy described in California
Civil Code Section 1951.4 (lessor may continue lease in effect after lessee's
breach and abandonment and recover rent as it becomes due, if lessee has the
right to sublet or assign, subject only to reasonable limitations). Accordingly,
if Landlord does not elect to terminate this Lease on account of any default by
Tenant, Landlord may, from time to time, without terminating this Lease, enforce
all of its rights and remedies under this Lease, including the right to recover
all rent as it becomes due.

                                      -36-
<PAGE>   43

                19.2.3 Landlord shall at all times have the rights and remedies
(which shall be cumulative with each other and cumulative and in addition to
those rights and remedies available under Sections 19.2.1 and 19.2.2, above, or
any law or other provision of this Lease), without prior demand or notice except
as required by applicable law, to seek any declaratory, injunctive or other
equitable relief, and specifically enforce this Lease, or restrain or enjoin a
violation or breach of any provision hereof.

        19.3 FORM OF PAYMENT AFTER DEFAULT. Following the occurrence of an event
of default by Tenant during the first twelve (12) months of the Lease Term,
Landlord shall have the right to require that any or all subsequent amounts paid
by Tenant to Landlord hereunder, whether to cure the default in question or
otherwise, be paid in the form of cash, money order, cashier's or certified
check drawn on an institution acceptable to Landlord, or by other means approved
by Landlord, notwithstanding any prior practice of accepting payments in any
different form.

        19.4 EFFORTS TO RELET. No re-entry or repossession, repairs,
maintenance, changes, alterations and additions, appointment of a receiver to
protect Landlord's interests hereunder, or any other action or omission by
Landlord shall be construed as an election by Landlord to terminate this Lease
or Tenant's right to possession, or to accept a surrender of the Premises, nor
shall same operate to release Tenant in whole or in part from any of Tenant's
obligations hereunder, unless express written notice of such intention is sent
by Landlord to Tenant.

        19.5 ABATEMENT OF RENT. In the event that Tenant is prevented from
using, and does not use, the Premises or any portion thereof, as a result of (i)
any alteration performed by Landlord after the Lease Commencement Date and
required by the Lease, which substantially interferes with Tenant's use of the
Premises, or (ii) any failure to provide services, utilities or access to the
Premises as required of Landlord pursuant to the terms of hereof (either such
set of circumstances as set forth in items (i) or (ii), above, to be known as an
"ABATEMENT EVENT"), then Tenant shall give Landlord notice of such Abatement
Event, and if such Abatement Event continues for seven (7) consecutive calendar
days after Landlord's receipt of any such notice (the "ELIGIBILITY PERIOD"),
then the Base Rent and Tenant's Share of Building Direct Expenses shall be
abated or reduced, as the case may be, after expiration of the Eligibility
Period for such time that Tenant continues to be so prevented from using, and
does not use, the Premises or a portion thereof, in the proportion that the
rentable area of the portion of the Premises that Tenant is prevented from
using, and does not use, bears to the total rentable area of the Premises;
provided, however, in the event that Tenant is prevented from using, and does
not use, a portion of the Premises for a period of time in excess of the
Eligibility Period and the remaining portion of the Premises is not sufficient
to allow Tenant to effectively conduct its business therein, and if Tenant does
not conduct its business from such remaining portion, then for such time after
expiration of the Eligibility Period during which Tenant is so prevented from
effectively conducting its business therein, the Base Rent and Tenant's Share of
Building Direct Expenses for the entire Premises shall be abated for such time
as Tenant continues to be so prevented from using, and does not use, the
Premises. If, however, Tenant reoccupies any portion of the Premises during such
period, the rent allocable to such reoccupied portion, based on the proportion
that the rentable area of such reoccupied portion of the Premises bears to the
total rentable area of the Premises, shall be payable by Tenant from the date
Tenant reoccupies such

                                      -37-
<PAGE>   44

portion of the Premises. Such right to abate Base Rent and Tenant's Share of
Building Direct Expenses shall be Tenant's sole and exclusive rent abatement
remedy at law or in equity for an Abatement Event. Except as provided in this
Section 19.5, nothing contained herein shall be interpreted to mean that Tenant
is excused from paying Rent due hereunder.

                                   ARTICLE 20

                           COVENANT OF QUIET ENJOYMENT

        Landlord covenants that Tenant, on paying the Rent, charges for services
and other payments herein reserved and on keeping, observing and performing all
the other terms, covenants, conditions, provisions and agreements herein
contained on the part of Tenant to be kept, observed and performed, shall,
during the Lease Term, peaceably and quietly have, hold and enjoy the Premises
subject to the terms, covenants, conditions, provisions and agreements hereof
without interference by any persons lawfully claiming by or through Landlord.
The foregoing covenant is in lieu of any other covenant express or implied.

                                   ARTICLE 21

                                SECURITY DEPOSIT

        Concurrent with Tenant's execution of this Lease, Tenant shall deposit
with Landlord a security deposit (the "SECURITY DEPOSIT") in the amount set
forth in Section 8 of the Summary, as security for the faithful performance by
Tenant of all of its obligations under this Lease. If Tenant defaults with
respect to any provisions of this Lease, including, but not limited to, the
provisions relating to the payment of Rent, the removal of property and the
repair of resultant damage, Landlord may, without notice to Tenant, but shall
not be required to, apply all or any part of the Security Deposit for the
payment of any Rent or any other sum in default and Tenant shall, upon demand
therefor, restore the Security Deposit to its original amount. Any unapplied
portion of the Security Deposit shall be returned to Tenant, or, at Landlord's
option, to the last assignee of Tenant's interest hereunder, within forty-five
(45) days following the expiration of the Lease Term. Tenant shall not be
entitled to any interest on the Security Deposit. Tenant hereby waives the
provisions of Section 1950.7 of the California Civil Code, or any successor
statute.

                                   ARTICLE 22

                              INTENTIONALLY DELETED

                                   ARTICLE 23

                                      SIGNS

        23.1 EXTERIOR SIGNAGE. Subject to Landlord's prior written approval, in
its reasonable discretion, and provided that any sign is in keeping with the
quality, design and style of the Building and Project and is in compliance with
all covenants, conditions or restrictions affecting the Project,

                                      -38-
<PAGE>   45

and all applicable law, Tenant, at its sole cost and expense, may install one
(1) sign identifying Tenant at the top of the Building facia, with the precise
location of such signage to be determined by Landlord.

        23.2 PROHIBITED SIGNAGE AND OTHER ITEMS. Any signs, notices, logos,
pictures, names or advertisements which are installed and that have not been
separately approved by Landlord may be removed without notice by Landlord at the
sole expense of Tenant. Except as is set forth in Section 23.1, above, Tenant
may not install any signs on the exterior or roof of the Building or the Common
Areas. Any signs, window coverings, or blinds (even if the same are located
behind the Landlord-approved window coverings for the Building), or other items
visible from the exterior of the Premises or Building, shall be subject to the
prior approval of Landlord, in its reasonable discretion.

                                   ARTICLE 24

                               COMPLIANCE WITH LAW

        Tenant shall not do anything or suffer anything to be done, by anyone
under Tenant's control, in or about the Premises or the Project which will in
any way violate any law, statute, ordinance or other governmental rule,
regulation or requirement now in force or which may hereafter be enacted or
promulgated concerning Tenant's use of the Premises. At its sole cost and
expense, Tenant shall promptly comply with all such governmental measures
relating to the Premises and Building, other than the making of changes to the
Base Building. Should any standard or regulation now or hereafter be imposed on
Landlord or Tenant concerning Tenant's use of the Premises by a state, federal
or local governmental body charged with the establishment, regulation and
enforcement of occupational, health or safety standards for employers,
employees, landlords or tenants, then Tenant agrees, at its sole cost and
expense, to comply promptly with such standards or regulations. The judgment of
any court of competent jurisdiction or the admission of Tenant in any judicial
action, regardless of whether Landlord is a party thereto, that Tenant has
violated any of said governmental measures, shall be conclusive of that fact as
between Landlord and Tenant.

                                   ARTICLE 25

                                  LATE CHARGES

        If any installment of Rent or any other sum due from Tenant shall not be
received by Landlord or Landlord's designee within five (5) days after Tenant's
receipt of a notice of non-payment by Landlord, then Tenant shall pay to
Landlord a late charge equal to five percent (5%) of the overdue amount by
reason of Tenant's failure to pay Rent and/or other charges when due hereunder.
The late charge shall be deemed Additional Rent and the right to require it
shall be in addition to all of Landlord's other rights and remedies hereunder or
at law and shall not be construed as liquidated damages or as limiting
Landlord's remedies in any manner. In addition to the late charge described
above, any Rent or other amounts owing hereunder which are not paid within ten
(10) days after the date they are due shall bear interest from the date when due
until paid at a rate per annum equal to the lesser of (i) the annual "Bank Prime
Loan" rate cited in the Federal Reserve

                                      -39-
<PAGE>   46

Statistical Release Publication G.13(415), published on the first Tuesday of
each calendar month (or such other comparable index as Landlord and Tenant shall
reasonably agree upon if such rate ceases to be published) plus two (2)
percentage points, and (ii) the highest rate permitted by applicable law.

                                   ARTICLE 26

              LANDLORD'S RIGHT TO CURE DEFAULT; PAYMENTS BY TENANT

        26.1 LANDLORD'S CURE. All covenants and agreements to be kept or
performed by Tenant under this Lease shall be performed by Tenant at Tenant's
sole cost and expense and without any reduction of Rent, except to the extent,
if any, otherwise expressly provided herein. If Tenant shall fail to perform any
obligation under this Lease, and such failure shall continue in excess of the
time allowed under Section 19.1.2, above, unless a specific time period is
otherwise stated in this Lease, Landlord may, but shall not be obligated to,
make any such payment or perform any such act on Tenant's part without waiving
its rights based upon any default of Tenant and without releasing Tenant from
any obligations hereunder.

        26.2 TENANT'S REIMBURSEMENT. Except as may be specifically provided to
the contrary in this Lease, Tenant shall pay to Landlord, upon delivery by
Landlord to Tenant of statements therefor: (i) sums equal to expenditures
reasonably made and obligations incurred by Landlord in connection with the
remedying by Landlord of Tenant's defaults pursuant to the provisions of Section
26.1; (ii) sums equal to all losses, costs, liabilities, damages and expenses
referred to in Article 10 of this Lease; and (iii) sums equal to all
expenditures made and obligations incurred by Landlord in collecting or
attempting to collect the Rent or in enforcing or attempting to enforce any
rights of Landlord under this Lease or pursuant to law, including, without
limitation, all legal fees and other amounts so expended. Tenant's obligations
under this Section 26.2 shall survive the expiration or sooner termination of
the Lease Term.

                                   ARTICLE 27

                                ENTRY BY LANDLORD

        Landlord reserves the right at all reasonable times and upon reasonable
notice to Tenant (except in the case of an emergency) to enter the Premises to
(i) inspect them; (ii) show the Premises to prospective purchasers, mortgagees
or tenants during the last seven (7) months of the Lease Term, or to current or
prospective mortgagees, ground or underlying lessors or insurers; (iii) post
notices of nonresponsibility; or (iv) alter, improve or repair the Premises or
the Building, or for structural alterations, repairs or improvements to the
Building or the Building's systems and equipment. Notwithstanding anything to
the contrary contained in this Article 27, Landlord may enter the Premises at
any time to (A) perform services required of Landlord, including janitorial
service; (B) take possession due to any breach of this Lease in the manner
provided herein; and (C) perform any covenants of Tenant which Tenant fails to
perform. Landlord may make any such entries without the abatement of Rent and
may take such reasonable steps as required to accomplish the stated purposes.
Tenant hereby waives any claims for damages or for any injuries or inconvenience
to or interference with Tenant's business, lost profits, any loss of occupancy
or quiet enjoyment of

                                      -40-
<PAGE>   47

the Premises, and any other loss occasioned by entry in accordance with this
Lease. For each of the above purposes, Landlord shall at all times have a key
with which to unlock all the doors in the Premises, excluding Tenant's vaults,
safes and special security areas designated in advance by Tenant. In an
emergency, Landlord shall have the right to use any means that Landlord may deem
proper to open the doors in and to the Premises. Any entry into the Premises by
Landlord in the manner hereinbefore described shall not be deemed to be a
forcible or unlawful entry into, or a detainer of, the Premises, or an actual or
constructive eviction of Tenant from any portion of the Premises. No provision
of this Lease shall be construed as obligating Landlord to perform any repairs,
alterations or decorations except as otherwise expressly agreed to be performed
by Landlord herein.

                                   ARTICLE 28

                                 TENANT PARKING

        Tenant shall have the right, during the Lease Term, to use up to the
number of parking spaces in the Project parking areas as set forth in Section 8
of the Summary. Such use shall be free of charge during the initial Lease Term.
Tenant shall abide by all reasonable rules and regulations which are prescribed
from time to time for the orderly operation and use of such areas, including any
sticker or other identification system established by Landlord, and Tenant's
cooperation in seeing that Tenant's employees and visitors also comply with such
rules and regulations. Landlord specifically reserves the right to change the
size, configuration, design, layout and all other aspects of the Project parking
areas at any time and Tenant acknowledges and agrees that Landlord may, without
incurring any liability to Tenant and without any abatement of Rent under this
Lease, from time to time, close-off or restrict access to the Project areas
facility for purposes of permitting or facilitating any such construction,
alteration or improvements. Landlord may delegate its responsibilities hereunder
to a parking operator in which case such parking operator shall have all the
rights of control attributed hereby to the Landlord.

                                   ARTICLE 29

                            MISCELLANEOUS PROVISIONS

        29.1 TERMS; CAPTIONS. The words "Landlord" and "Tenant" as used herein
shall include the plural as well as the singular. The necessary grammatical
changes required to make the provisions hereof apply either to corporations or
partnerships or individuals, men or women, as the case may require, shall in all
cases be assumed as though in each case fully expressed. The captions of
Articles and Sections are for convenience only and shall not be deemed to limit,
construe, affect or alter the meaning of such Articles and Sections.

        29.2 BINDING EFFECT. Subject to all other provisions of this Lease, each
of the covenants, conditions and provisions of this Lease shall extend to and
shall, as the case may require, bind or inure to the benefit not only of
Landlord and of Tenant, but also of their respective heirs, personal
representatives, successors or assigns, provided this clause shall not permit
any assignment by Tenant contrary to the provisions of Article 14 of this Lease.

                                      -41-
<PAGE>   48

        29.3 NO AIR RIGHTS. No rights to any view or to light or air over any
property, whether belonging to Landlord or any other person, are granted to
Tenant by this Lease. If at any time any windows of the Premises are temporarily
darkened or the light or view therefrom is obstructed by reason of any repairs,
improvements, maintenance or cleaning in or about the Project, the same shall be
without liability to Landlord and without any reduction or diminution of
Tenant's obligations under this Lease.

        29.4 MODIFICATION OF LEASE. Should any current or prospective mortgagee
or ground lessor for the Building or Project require a modification of this
Lease, which modification will not cause an increased cost or expense to Tenant
or in any other way materially and adversely change the rights and obligations
of Tenant hereunder, then and in such event, Tenant agrees that this Lease may
be so modified and agrees to execute whatever documents are reasonably required
therefor and to deliver the same to Landlord within ten (10) days following a
request therefor. At the request of Landlord or any mortgagee or ground lessor,
Tenant agrees to execute a short form of Lease and deliver the same to Landlord
within ten (10) days following the request therefor.

        29.5 TRANSFER OF LANDLORD'S INTEREST. Tenant acknowledges that Landlord
has the right to transfer all or any portion of its interest in the Project or
Building and in this Lease, and Tenant agrees that in the event of any such
transfer, Landlord shall automatically be released from all liability under this
Lease accruing after the date of such transfer, and to the extent such
obligation becomes the obligation of the Transferee, agrees to look solely to
such transferee for the performance of Landlord's obligations hereunder after
the date of transfer and such transferee shall be deemed to have fully assumed
and be liable for all obligations of this Lease to be performed by Landlord,
including the return of any Security Deposit, and Tenant shall attorn to such
transferee.

        29.6 PROHIBITION AGAINST RECORDING. Except as provided in Section 29.4
of this Lease, neither this Lease, nor any memorandum, affidavit or other
writing with respect thereto, shall be recorded by Tenant or by anyone acting
through, under or on behalf of Tenant.

        29.7 LANDLORD'S TITLE. Landlord's title is and always shall be paramount
to the title of Tenant. Nothing herein contained shall empower Tenant to do any
act which can, shall or may encumber the title of Landlord.

        29.8 RELATIONSHIP OF PARTIES. Nothing contained in this Lease shall be
deemed or construed by the parties hereto or by any third party to create the
relationship of principal and agent, partnership, joint venturer or any
association between Landlord and Tenant.

        29.9 APPLICATION OF PAYMENTS. Landlord shall have the right to apply
payments received from Tenant pursuant to this Lease, regardless of Tenant's
designation of such payments, to satisfy any obligations of Tenant hereunder, in
such order and amounts as Landlord, in its sole discretion, may elect.

        29.10 TIME OF ESSENCE. Time is of the essence with respect to the
performance of every provision of this Lease in which time of performance is a
factor.

                                      -42-
<PAGE>   49

        29.11 PARTIAL INVALIDITY. If any term, provision or condition contained
in this Lease shall, to any extent, be invalid or unenforceable, the remainder
of this Lease, or the application of such term, provision or condition to
persons or circumstances other than those with respect to which it is invalid or
unenforceable, shall not be affected thereby, and each and every other term,
provision and condition of this Lease shall be valid and enforceable to the
fullest extent possible permitted by law.

        29.12 NO WARRANTY. In executing and delivering this Lease, Tenant has
not relied on any representations, including, but not limited to, any
representation as to the amount of any item comprising Additional Rent or the
amount of the Additional Rent in the aggregate or that Landlord is furnishing
the same services to other tenants, at all, on the same level or on the same
basis, or any warranty or any statement of Landlord which is not set forth
herein or in one or more of the exhibits attached hereto.

        29.13 LANDLORD EXCULPATION. The liability of Landlord or the Landlord
Parties to Tenant for any default by Landlord under this Lease or arising in
connection herewith or with Landlord's operation, management, leasing, repair,
renovation, alteration or any other matter relating to the Project or the
Premises shall be limited solely and exclusively to an amount which is equal to
the interest of Landlord in the Building. Neither Landlord, nor any of the
Landlord Parties shall have any personal liability therefor, and Tenant hereby
expressly waives and releases such personal liability on behalf of itself and
all persons claiming by, through or under Tenant. The limitations of liability
contained in this Section 29.13 shall inure to the benefit of Landlord's and the
Landlord Parties' present and future partners, beneficiaries, officers,
directors, trustees, shareholders, agents and employees, and their respective
partners, heirs, successors and assigns. Under no circumstances shall any
present or future partner of Landlord (if Landlord is a partnership), or trustee
or beneficiary (if Landlord or any partner of Landlord is a trust), have any
liability for the performance of Landlord's obligations under this Lease.
Notwithstanding any contrary provision herein, neither Landlord nor the Landlord
Parties shall be liable under any circumstances for injury or damage to, or
interference with, Tenant's business, including but not limited to, loss of
profits, loss of rents or other revenues, loss of business opportunity, loss of
goodwill or loss of use, in each case, however occurring.

        29.14 ENTIRE AGREEMENT. This Lease and any Exhibits hereto constitute
the entire agreement of the parties. It is understood and acknowledged that
there are no oral agreements between the parties hereto affecting this Lease and
this Lease constitutes the parties' entire agreement with respect to the leasing
of the Premises and supersedes and cancels any and all previous negotiations,
arrangements, brochures, agreements and understandings, if any, between the
parties hereto or displayed by Landlord to Tenant with respect to the subject
matter thereof, and none thereof shall be used to interpret or construe this
Lease. None of the terms, covenants, conditions or provisions of this Lease can
be modified, deleted or added to except in writing signed by the parties hereto.

        29.15 RIGHT TO LEASE. Landlord reserves the absolute right to effect
such other tenancies in the Project as Landlord in the exercise of its sole
business judgment shall determine to best promote the interests of the Building
or Project. Tenant does not rely on the fact, nor does Landlord

                                      -43-
<PAGE>   50

represent, that any specific tenant or type or number of tenants shall, during
the Lease Term, occupy any space in the Building or Project.

        29.16 FORCE MAJEURE. Any prevention, delay or stoppage due to strikes,
lockouts, labor disputes, acts of God, inability to obtain services, labor, or
materials or reasonable substitutes therefor, governmental actions, civil
commotions, fire or other casualty, and other causes beyond the reasonable
control of the party obligated to perform, except with respect to the
obligations imposed with regard to Rent and other charges to be paid by Tenant
pursuant to this Lease (collectively, a "FORCE MAJEURE"), notwithstanding
anything to the contrary contained in this Lease, shall excuse the performance
of such party for a period equal to any such prevention, delay or stoppage and,
therefore, if this Lease specifies a time period for performance of an
obligation of either party, that time period shall be extended by the period of
any delay in such party's performance caused by a Force Majeure.

        29.17 WAIVER OF REDEMPTION BY TENANT. Tenant hereby waives, for Tenant
and for all those claiming under Tenant, any and all rights now or hereafter
existing to redeem by order or judgment of any court or by any legal process or
writ, Tenant's right of occupancy of the Premises after any termination of this
Lease.

        29.18 NOTICES. All notices, demands, statements, designations, approvals
or other communications (collectively, "NOTICES") given or required to be given
by either party to the other hereunder or by law shall be in writing, shall be
(A) sent by United States certified or registered mail, postage prepaid, return
receipt requested ("MAIL"), (B) delivered by a nationally recognized overnight
courier, or (C) delivered personally. Any Notice shall be sent, transmitted, or
delivered, as the case may be, to Tenant at the appropriate address set forth in
Section 10 of the Summary, or to such other place as Tenant may from time to
time designate in a Notice to Landlord, or to Landlord at the addresses set
forth in Section 11 of the Summary, or to such other places as Landlord may from
time to time designate in a Notice to Tenant. Any Notice will be deemed given
(i) three (3) business days after the date it is posted if sent by Mail, (ii)
the date the overnight courier delivery is received, or (iii) the date personal
delivery is made.

        29.19 JOINT AND SEVERAL. If there is more than one Tenant, the
obligations imposed upon Tenant under this Lease shall be joint and several.

        29.20 AUTHORITY. If Tenant is a corporation, trust or partnership,
Tenant hereby represents and warrants that Tenant is a duly formed and existing
entity qualified to do business in California and that Tenant has full right and
authority to execute and deliver this Lease and that each person signing on
behalf of Tenant is authorized to do so. In such event, Tenant shall, within ten
(10) days after execution of this Lease, deliver to Landlord satisfactory
evidence of such authority and, if a corporation, upon demand by Landlord, also
deliver to Landlord satisfactory evidence of (i) good standing in Tenant's state
of incorporation and (ii) qualification to do business in California.

        29.21 ATTORNEYS' FEES. In the event that either Landlord or Tenant
should bring suit for the possession of the Premises, for the recovery of any
sum due under this Lease, or because of the breach of any provision of this
Lease or for any other relief against the other, then all costs and

                                      -44-
<PAGE>   51

expenses, including reasonable attorneys' fees, incurred by the prevailing party
therein shall be paid by the other party, which obligation on the part of the
other party shall be deemed to have accrued on the date of the commencement of
such action and shall be enforceable whether or not the action is prosecuted to
judgment.

        29.22 GOVERNING LAW; WAIVER OF TRIAL BY JURY. This Lease shall be
construed and enforced in accordance with the laws of the State of California.
IN ANY ACTION OR PROCEEDING ARISING HEREFROM, LANDLORD AND TENANT HEREBY CONSENT
TO (I) THE JURISDICTION OF ANY COMPETENT COURT WITHIN THE STATE OF CALIFORNIA,
(II) SERVICE OF PROCESS BY ANY MEANS AUTHORIZED BY CALIFORNIA LAW, AND (III) IN
THE INTEREST OF SAVING TIME AND EXPENSE, TRIAL WITHOUT A JURY IN ANY ACTION,
PROCEEDING OR COUNTERCLAIM BROUGHT BY EITHER OF THE PARTIES HERETO AGAINST THE
OTHER OR THEIR SUCCESSORS IN RESPECT OF ANY MATTER ARISING OUT OF OR IN
CONNECTION WITH THIS LEASE, THE RELATIONSHIP OF LANDLORD AND TENANT, TENANT'S
USE OR OCCUPANCY OF THE PREMISES, AND/OR ANY CLAIM FOR INJURY OR DAMAGE, OR ANY
EMERGENCY OR STATUTORY REMEDY. IN THE EVENT LANDLORD COMMENCES ANY SUMMARY
PROCEEDINGS OR ACTION FOR NONPAYMENT OF BASE RENT OR ADDITIONAL RENT, TENANT
SHALL NOT INTERPOSE ANY COUNTERCLAIM OF ANY NATURE OR DESCRIPTION (UNLESS SUCH
COUNTERCLAIM SHALL BE MANDATORY) IN ANY SUCH PROCEEDING OR ACTION, BUT SHALL BE
RELEGATED TO AN INDEPENDENT ACTION AT LAW.

        29.23 SUBMISSION OF LEASE. Submission of this instrument for examination
or signature by Tenant does not constitute a reservation of, option for or
option to lease, and it is not effective as a lease or otherwise until execution
and delivery by both Landlord and Tenant.

        29.24 BROKERS. Landlord and Tenant hereby warrant to each other that
they have had no dealings with any real estate broker or agent in connection
with the negotiation of this Lease, excepting only the real estate brokers or
agents specified in Section 11 of the Summary (the "BROKERS"), and that they
know of no other real estate broker or agent who is entitled to a commission in
connection with this Lease. Each party agrees to indemnify and defend the other
party against and hold the other party harmless from any and all claims,
demands, losses, liabilities, lawsuits, judgments, costs and expenses (including
without limitation reasonable attorneys' fees) with respect to any leasing
commission or equivalent compensation alleged to be owing on account of any
dealings with any real estate broker or agent, other than the Brokers, occurring
by, through, or under the indemnifying party.

        29.25 INDEPENDENT COVENANTS. This Lease shall be construed as though the
covenants herein between Landlord and Tenant are independent and not dependent
and Tenant hereby expressly waives the benefit of any statute to the contrary
and agrees that if Landlord fails to perform its obligations set forth herein,
Tenant shall not be entitled to make any repairs or perform any acts hereunder
at Landlord's expense or to any setoff of the Rent or other amounts owing
hereunder against Landlord.

                                      -45-
<PAGE>   52

        29.26 PROJECT OR BUILDING NAME AND SIGNAGE. Landlord shall have the
right at any time to change the name of the Project or Building and to install,
affix and maintain any and all signs on the exterior and on the interior of the
Project or Building as Landlord may, in Landlord's sole discretion, desire.
Tenant shall not use the words "Irvine Oaks" or the name of the Project or
Building or use pictures or illustrations of the Project or Building in
advertising or other publicity or for any purpose other than as the address of
the business to be conducted by Tenant in the Premises, without the prior
written consent of Landlord.

        29.27 COUNTERPARTS. This Lease may be executed in counterparts with the
same effect as if both parties hereto had executed the same document. Both
counterparts shall be construed together and shall constitute a single lease.

        29.28 CONFIDENTIALITY. Tenant acknowledges that the content of this
Lease and any related documents are confidential information. Tenant shall keep
such confidential information strictly confidential and shall not disclose such
confidential information to any person or entity other than Tenant's financial,
legal, and space planning consultants.

        29.29 DEVELOPMENT OF THE PROJECT.

                29.29.1 SUBDIVISION. Landlord reserves the right to further
subdivide all or a portion of the Project. Tenant agrees to execute and deliver,
upon demand by Landlord and in the form requested by Landlord, any additional
documents needed to conform this Lease to the circumstances resulting from such
subdivision.

                29.29.2 THE OTHER IMPROVEMENTS. If portions of the Project or
property adjacent to the Project (collectively, the "OTHER IMPROVEMENTS") are
owned by an entity other than Landlord, Landlord, at its option, may enter into
an agreement with the owner or owners of any or all of the Other Improvements to
provide (i) for reciprocal rights of access and/or use of the Project and the
Other Improvements, (ii) for the common management, operation, maintenance,
improvement and/or repair of all or any portion of the Project and the Other
Improvements, (iii) for the allocation of a portion of the Direct Expenses to
the Other Improvements and the operating expenses and taxes for the Other
Improvements to the Project, and (iv) for the use or improvement of the Other
Improvements and/or the Project in connection with the improvement,
construction, and/or excavation of the Other Improvements and/or the Project so
long as the rights and obligations of Tenant hereunder are not materially
adversely affected by any such agreements entered into by Landlord. Nothing
contained herein shall be deemed or construed to limit or otherwise affect
Landlord's right to convey all or any portion of the Project or any other of
Landlord's rights described in this Lease.

                29.29.3 CONSTRUCTION OF PROJECT AND OTHER IMPROVEMENTS. Tenant
acknowledges that portions of the Project and/or the Other Improvements may be
under construction following Tenant's occupancy of the Premises, and that such
construction may result in levels of noise, dust, obstruction of access, etc.
which are in excess of that present in a fully constructed project. Tenant
hereby waives any and all rent offsets or claims of constructive eviction which
may arise in connection with such construction.

                                      -46-
<PAGE>   53

        29.30 BUILDING RENOVATIONS. It is specifically understood and agreed
that Landlord has no obligation and has made no promises to alter, remodel,
improve, renovate, repair or decorate the Premises, Building, or any part
thereof and that no representations respecting the condition of the Premises or
the Building have been made by Landlord to Tenant except as specifically set
forth herein or in the Tenant Work Letter. However, Tenant hereby acknowledges
that Landlord is currently renovating or may during the Lease Term renovate,
improve, alter, or modify (collectively, the "RENOVATIONS") the Project, the
Building and/or the Premises. Tenant hereby agrees that such Renovations shall
in no way constitute a constructive eviction of Tenant.

        29.31 NO VIOLATION. Tenant hereby warrants and represents that neither
its execution of nor performance under this Lease shall cause Tenant to be in
violation of any agreement, instrument, contract, law, rule or regulation by
which Tenant is bound, and Tenant shall protect, defend, indemnify and hold
Landlord harmless against any claims, demands, losses, damages, liabilities,
costs and expenses, including, without limitation, reasonable attorneys' fees
and costs, arising from Tenant's breach of this warranty and representation.

        IN WITNESS WHEREOF, Landlord and Tenant have caused this Lease to be
executed the day and date first above written.

                                       "LANDLORD":

                                       IRVINE OAKS REALTY HOLDING CO., INC.,
                                       a Delaware corporation

                                       By:
                                           -------------------------------------

                                       Its:
                                            ------------------------------------

                                       "TENANT":

                                       GADZOOX NETWORKS, INC.,
                                       a Delaware corporation

                                       By:
                                           -------------------------------------

                                       Its:
                                            ------------------------------------

                                       By:
                                           -------------------------------------

                                       Its:
                                            ------------------------------------

                                      -47-
<PAGE>   54

                                    EXHIBIT A

                               OUTLINE OF PREMISES

                        [Schematic Diagram Inserted Here]

<PAGE>   55

                                    EXHIBIT B

                           IRVINE OAKS EXECUTIVE PARK

                               TENANT WORK LETTER

        This Tenant Work Letter shall set forth the terms and conditions
relating to the construction of the tenant improvements in the Premises. This
Tenant Work Letter is essentially organized chronologically and addresses the
issues of the construction of the Premises, in sequence, as such issues will
arise during the actual construction of the Premises. All references in this
Tenant Work Letter to Articles or Sections of "this Lease" shall mean the
relevant portion of Articles 1 through 29 of the Standard Form Office Lease to
which this Tenant Work Letter is attached as Exhibit B and of which this Tenant
Work Letter forms a part, and all references in this Tenant Work Letter to
Sections of "this Tenant Work Letter" shall mean the relevant portion of
Sections 1 through 6 of this Tenant Work Letter.

                                    SECTION 1

                 LANDLORD'S INITIAL CONSTRUCTION IN THE PREMISES

        1.1 Base Building as Constructed by Landlord. Landlord has constructed,
at its sole cost and expense, the base, shell and core as the Premises and the
Building (collectively, the "BASE BUILDING"). Tenant shall accept the Base
Building in its presently existing, as is condition, provided that Landlord
agrees to cause such Base Building to be in compliance with applicable building
code and other laws, statutes, and governmental regulations (collectively,
"CODE") to the extent required to allow Tenant to legally occupy the Premises.

                                    SECTION 2

                               TENANT IMPROVEMENTS

        2.1 Tenant Improvement Allowance. Tenant shall be entitled to a one-time
tenant improvement allowance (the "TENANT IMPROVEMENT ALLOWANCE") in the amount
of $27.00 for each of the 12,420 usable square feet of the Premises for the
costs relating to the initial design and construction of Tenant's improvements
which are permanently affixed to the Premises (the "TENANT IMPROVEMENTS"). In no
event shall Landlord be obligated to make disbursements pursuant to this Tenant
Work Letter in a total amount which exceeds the Tenant Improvement Allowance.
Tenant shall have the right to use an additional amount (the "ADDITIONAL TENANT
IMPROVEMENT ALLOWANCE"), not to exceed $4.00 for each of the 12,420 usable
square feet of the Premises, to be used towards the cost of the Tenant
Improvements. Tenant agrees that, in order repay the Additional Tenant
Improvement Allowance used by Tenant if any, to Landlord, the monthly Base Rent
for the Premises shall be increased by an amount equal to the "Additional
Monthly Base Rent", as that term is defined below. The "Additional Monthly Base
Rent" shall be determined as the missing component of an annuity, which annuity
shall have (i) the amount of the Additional Tenant

<PAGE>   56

Improvement Allowance used by Tenant as the present value amount, (ii) 60 as the
number of payments (i.e., the number of months in the initial Lease Term as to
which Tenant is obligated to pay Base Rent), (iii) eighty-three one hundredths
of one percent (0.83%), which is equal to ten percent (10%) divided by twelve
(12) months per year, as the monthly interest factor, and (iv) the Additional
Monthly Base Rent as the missing component of the annuity.

        2.2 Disbursement of the Tenant Improvement Allowance. Except as
otherwise set forth in this Tenant Work Letter, the Tenant Improvement Allowance
shall be disbursed by Landlord (each of which disbursements shall be made
pursuant to Landlord's disbursement process) for costs related to the
construction of the Tenant Improvements and for the following items and costs
(collectively, the "TENANT IMPROVEMENT ALLOWANCE ITEMS"): (i) payment of the
fees of the "Architect" and the "Engineers," as those terms are defined in
Section 3.1 of this Tenant Work Letter, and payment of the fees incurred by, and
the cost of documents and materials supplied by, Landlord and Landlord's
consultants in connection with the preparation and review of the "Construction
Drawings," as that term is defined in Section 3.1 of this Tenant Work Letter;
(ii) the cost of any changes in the Base Building when such changes are required
by the Construction Drawings and approved by Tenant; (iii) the cost of any
changes to the Construction Drawings or Tenant Improvements required by Code and
approved by Tenant; (iv) the "Landlord Supervision Fee," as that term is defined
in Section 4.3.2 of this Tenant Work Letter; (v) a portion of the costs of the
tenant demising walls and public corridor walls and materials, if any, as
designated by Landlord.

        2.3 Standard Tenant Improvement Package. Landlord has established
specifications (the "SPECIFICATIONS") for the Building standard components to be
used in the construction of the Tenant Improvements in the Premises
(collectively, the "STANDARD IMPROVEMENT PACKAGE"), which Specifications shall
be supplied to Tenant by Landlord. Except as otherwise approved by Landlord in
connection with the creation of the Construction Drawings (defined below), the
quality of Tenant Improvements shall be equal to or of greater quality than the
quality of the Specifications, provided that Landlord may, at Landlord's option,
require the Tenant Improvements to comply with certain Specifications.

                                    SECTION 3

                              CONSTRUCTION DRAWINGS

        3.1 Selection of Architect/Construction Drawings. Landlord shall retain
an architect designated by Tenant and reasonably approved by Landlord (the
"ARCHITECT") to prepare the "Construction Drawings," as that term is defined in
this Section 3.1. Landlord shall retain the engineering consultants designated
by Landlord (the "ENGINEERS") to prepare all plans and engineering working
drawings relating to the structural, mechanical, electrical, plumbing, HVAC,
lifesafety, and sprinkler work of the Tenant Improvements. The plans and
drawings to be prepared by Architect and the Engineers hereunder shall be known
collectively as the "Construction Drawings." All Construction Drawings shall
comply with the drawing format and specifications as determined by Landlord, and
shall be subject to Tenant's approval.

                               EXHIBIT B - Page 2
<PAGE>   57

        3.2 Final Space Plan. That certain space plan prepared by Architect and
dated ______________, 1999, is herein referred to as the "FINAL SPACE PLAN".

        3.3 Final Working Drawings. On or before the date set forth in Schedule
1, the Architect and the Engineers shall complete the architectural and
engineering drawings for the Premises, and the final architectural working
drawings in a form which is complete to allow subcontractors to bid on the work
and to obtain all applicable permits (collectively, the "FINAL WORKING
DRAWINGS") and shall submit the same to Tenant for Tenant's reasonable approval.
Tenant shall respond with its approval of the Final Working Drawings, or with
detailed reasons for its disapproval, within seven (7) business days after
Tenant's receipt thereof. Tenant shall have no right to disapprove any aspect of
the Final Working Drawings which is consistent with the Final Space Plan, or
with a previously approved version of the Final Working Drawings.

        3.4 Permits. The Final Working Drawings shall be approved by Landlord
and Tenant (the "APPROVED WORKING DRAWINGS") prior to the commencement of the
construction of the Tenant Improvements. Landlord shall promptly submit the
Approved Working Drawings to the appropriate municipal authorities for all
applicable building permits necessary to allow "Contractor," as that term is
defined in Section 4.1, below, to commence and fully complete the construction
of the Tenant Improvements (the "PERMITS"). Tenant shall cooperate with Landlord
in executing permit applications and performing other ministerial acts
reasonably necessary to enable Landlord to obtain any such permit or certificate
of occupancy. No changes, modifications or alterations in the Approved Working
Drawings may be made without the prior written consent of Landlord and Tenant.

        3.5 Time Deadlines. Landlord and Tenant shall use its good faith
commercially reasonable efforts and due diligence to cooperate with the
Architect and the Engineers to complete all phases of the Construction Drawings
and the permitting process and to receive the permits, and with Contractor for
approval of the "Cost Proposal," as that term is defined in Section 4.2 of this
Tenant Work Letter, as soon as possible after the execution of the Lease, and,
in that regard, shall meet with on a scheduled basis to be mutually agreed upon,
to discuss progress in connection with the same. The applicable dates for
approval of items, plans and drawings as described in this Section 3, Section 4,
below, and in this Tenant Work Letter are referred to as the "TIME DEADLINES".
Landlord and Tenant agree to comply with the Time Deadlines. Landlord further
agrees to cause Contractor to use its best efforts to comply with such Time
Deadlines, and timely notify Landlord and Tenant of any changes foreseen by
Contractor with respect thereto.

                                    SECTION 4

                     CONSTRUCTION OF THE TENANT IMPROVEMENTS

        4.1 Contractor. Magellan Construction ("CONTRACTOR") shall construct the
Tenant Improvements. Contractor shall perform all work in connection with the
Tenant Improvements in a manner consistent with that of expert contracting firms
involved in projects of similar scope and complexity, and in accordance with the
requirements of the Approved Working Drawings. The form of agreement to be
entered into by Owner and Contractor shall be in the form of or a form

                               EXHIBIT B - Page 3
<PAGE>   58

substantially similar to a Standard Form of Agreement between Owner and
Contractor where the basis for payment is the Cost of the Work Plus a Fee with a
negotiated Guaranteed Maximum Price (the "Construction Contract"), with such
Guaranteed Maximum Price to be based on the approved "Cost Proposal," defined
below. Contractor shall competitively bid the Tenant Improvements with at least
three (3) subcontractors for each major trade with a total cost over $20,000,
two (2) of which may be designated by Tenant.

        4.2 Cost Proposal. Within five (5) business days after the Approved
Working Drawings are signed by Landlord and Tenant, and the bids are received
from the applicable subcontractors and suppliers, Landlord shall provide Tenant
with a "not-to-exceed" cost proposal in accordance with the Approved Working
Drawings, which cost proposal shall include, as nearly as possible, the total
cost of the work and cost of all Tenant Improvement Allowance Items to be paid
by Tenant in connection with the design and construction of the Tenant
Improvements (the "COST PROPOSAL"). Tenant shall review and disapprove or
approve and deliver the Cost Proposal to Landlord within five (5) business days
of the receipt of the same, and upon Landlord's receipt of Tenant's approval of
the same, Landlord shall be released by Tenant to purchase the items set forth
in the Cost Proposal and to commence the construction relating to such items.
The date by which Tenant must approve and deliver the Cost Proposal to Landlord
shall be known hereafter as the "COST PROPOSAL DELIVERY DATE".

        4.3 Construction of Tenant Improvements by Contractor under the
Supervision of Landlord.

                4.3.1 Over-Allowance Amount. On the Cost Proposal Delivery Date,
Tenant shall deliver to Landlord cash in an amount (the "OVER-ALLOWANCE AMOUNT")
equal to the difference between (i) the amount of the Cost Proposal and (ii) the
amount of the Tenant Improvement Allowance, plus any Additional Tenant
Improvement Allowance. The Over-Allowance Amount shall be disbursed by Landlord
pursuant to the same procedure as the Tenant Improvement Allowance. In the event
that, after the Cost Proposal Delivery Date, any revisions, changes, or
substitutions shall be made to the Construction Drawings or the Tenant
Improvements, any additional costs which arise in connection with such
revisions, changes or substitutions or any other additional costs shall be paid
by Tenant to Landlord immediately upon Landlord's request as an addition to the
Over-Allowance Amount. Notwithstanding the foregoing, in the event that Tenant
requests any change to the Approved Working Drawings ("Change"), which Change
may result in an additive or deductive change in the guaranteed maximum amount
("GMAX") of the Construction Contract, Landlord shall obtain from the Contractor
and provide Tenant a copy of a binding change order ("Change Order") setting
forth the fixed amount of increase, if any, or decrease, if any, in the GMAX and
the extension of time, if any, required in the event such Changes are
implemented. Within three (3) business days following Tenant's receipt of the
proposed Change Order, Tenant shall either approve the proposed Change Order (in
which case the Changes will be implemented promptly by the Contractor), or
disapprove the same (in which case the Changes will not be implemented).
Notwithstanding any provision of this Tenant Work Letter to the contrary, no
request for a Change or any other activity related to a Change shall constitute
a Tenant Delay unless and

                               EXHIBIT B - Page 4
<PAGE>   59

until (i) the same qualifies as a Tenant Delay under Section 5.2, below, and
(ii) such Change and Change Order with respect thereto is approved in writing by
Tenant.

                4.3.2 Landlord's Retention of Contractor. Landlord shall
independently retain Contractor, on behalf of Tenant, to construct the Tenant
Improvements in accordance with the Approved Working Drawings and the Cost
Proposal. Landlord shall supervise the construction by Contractor, and Tenant
shall pay a construction supervision and management fee (the "LANDLORD
SUPERVISION FEE") to Landlord in an amount equal to the product of (i) three
percent (3%) and (ii) an amount equal to the Tenant Improvement Allowance, plus
any Additional Tenant Improvement Allowance, plus the Over-Allowance Amount (as
such Over-Allowance Amount may increase pursuant to the terms of this Tenant
Work Letter).

                4.3.3 Contractor's Warranties and Guaranties. Landlord hereby
assigns to Tenant all warranties and guaranties by Contractor relating to the
Tenant Improvements, and Tenant hereby waives all claims against Landlord
relating to, or arising out of the construction of, the Tenant Improvements.
Notwithstanding the foregoing, Landlord agrees that it shall be responsible to
repair any latent construction defects in the Tenant Improvements which are
discovered during the first Lease Year.

                                    SECTION 5

                     COMPLETION OF THE TENANT IMPROVEMENTS;
                             LEASE COMMENCEMENT DATE

        5.1 Ready for Occupancy. The Premises shall be deemed "READY FOR
OCCUPANCY" upon the Substantial Completion of the Premises, and the issuance of
a certificate of occupancy or its legal equivalent allowing legal occupancy of
the Premises. For purposes of this Lease, "SUBSTANTIAL COMPLETION" of the
Premises shall occur upon the completion of construction of the Tenant
Improvements in the Premises in accordance with the Approved Working Drawings,
with the exception of any punch list items which do not unreasonably interfere
with Tenant's use of the Premises and any tenant fixtures, work-stations,
built-in furniture, or equipment to be installed by Tenant or under the
supervision of Contractor.

        5.2 Delay of the Substantial Completion of the Premises. Except as
provided in this Section 5.2, the Lease Commencement Date shall occur as set
forth in Article 2 of the Lease and Section 5.1, above. If there shall be a
delay or there are delays in the Substantial Completion of the Premises or in
the occurrence of any of the other conditions precedent to the Lease
Commencement Date, as set forth in Article 2 of the Lease, as a direct,
indirect, partial, or total result of:

                5.2.1 Tenant's failure to comply with the Time Deadlines;

                5.2.2 Tenant's failure to timely approve any matter requiring
Tenant's approval;

                5.2.3 A breach by Tenant of the terms of this Tenant Work Letter
or the Lease;

                               EXHIBIT B - Page 5
<PAGE>   60

                5.2.4 Changes in any of the Construction Drawings after
disapproval of the same by Landlord or because the same do not comply with Code
or other applicable laws;

                5.2.5 Tenant's request for changes in the Approved Working
Drawings in accordance with Section 4.3 above;

                5.2.6 Tenant's requirement for materials, components, finishes
or improvements which are not available in a commercially reasonable time given
the anticipated date of Substantial Completion of the Premises, as set forth in
the Lease, or which are different from, or not included in, the Standard
Improvement Package;

                5.2.7 Changes to the Base Building required by the Approved
Working Drawings; or

                5.2.8 Any other acts or omissions of Tenant, or its agents, or
employees;

then, notwithstanding anything to the contrary set forth in the Lease or this
Tenant Work Letter and regardless of the actual date of the Substantial
Completion of the Premises, the Lease Commencement Date shall be deemed to be
the date the Lease Commencement Date would have occurred if no Tenant delay or
delays, as set forth above, had occurred.

        5.3 Inspection; Latent Defects.

                5.3.1 Inspection. Following the Substantial Completion of the
Premises and prior to Tenant's move into the Premises, Landlord, Contractor and
Tenant shall inspect the Premises and complete a punch list of unfinished items
of the Tenant Improvements. Authorized representatives for Landlord and Tenant
shall execute said punch list to indicate their approval thereof, Landlord shall
cause the items listed on each such punch list to be completed by Contractor as
soon after preparation of such punch list as is reasonably practicable (but in
no event to exceed thirty (30) days thereafter).

                5.3.2 Latent Defects. In the event that after preparation of the
punch list described in Section 5.3.1, and during the first (1st) Lease Year,
Tenant discovers additional latent defects in the Tenant Improvements, within a
reasonable period following notice of the same to Landlord, Landlord will, with
reasonable diligence, cause Contractor to commence and thereafter pursue to
completion a full cure for such defect and bring the Tenant Improvements into
the condition required by the Construction Contract.

                                    SECTION 6

                                  MISCELLANEOUS

        6.1 Tenant's Entry Into the Premises Prior to Substantial Completion.
Provided that Tenant and its agents do not unreasonably interfere with
Contractor's work in the Building and the Premises, Contractor shall allow
Tenant access to the Premises prior to the Substantial Completion

                               EXHIBIT B - Page 6
<PAGE>   61

of the Premises for the purpose of Tenant installing its furnishings, equipment
or fixtures (including Tenant's data and telephone equipment), not included in
the Tenant Improvements, in the Premises. Prior to Tenant's entry into the
Premises as permitted by the terms of this Section 6.1, Tenant shall submit a
schedule to Landlord and Contractor, for their approval, which schedule shall
detail the timing and purpose of Tenant's entry. Subject to the terms of Article
10 of the Lease, Tenant shall hold Landlord harmless from and indemnify, protect
and defend Landlord against any loss or damage to the Building or Premises and
against injury to any persons caused by Tenant's actions pursuant to this
Section 6.1.

        6.2 Tenant's Representative. Tenant has designated Jan Ciano as its sole
representative with respect to the matters set forth in this Tenant Work Letter,
who, until further notice to Landlord, shall have full authority and
responsibility to act on behalf of the Tenant as required in this Tenant Work
Letter.

        6.3 Landlord's Representative. Landlord has designated Joseph Bernhard
as its sole representative with respect to the matters set forth in this Tenant
Work Letter, who, until further notice to Tenant, shall have full authority and
responsibility to act on behalf of the Landlord as required in this Tenant Work
Letter.

        6.4 Time of the Essence in This Tenant Work Letter. Unless otherwise
indicated, all references herein to a "number of days" shall mean and refer to
calendar days.

        6.6 Tenant's Lease Default. Notwithstanding any provision to the
contrary contained in this Lease, during an event of default as described in
Section 19.1 of the Lease, or a default by Tenant under this Tenant Work Letter,
after expiration of any applicable notice and cure period, then (i) in addition
to all other rights and remedies granted to Landlord pursuant to the Lease,
Landlord shall have the right to withhold payment of all or any portion of the
Tenant Improvement Allowance and/or Landlord may cause Contractor to cease the
construction of the Premises (in which case, Tenant shall be responsible for any
delay in the Substantial Completion of the Premises caused by such work stoppage
as set forth in Section 5 of this Tenant Work Letter), and (ii) all other
obligations of Landlord under the terms of this Tenant Work Letter shall be
forgiven until such time as such default is cured pursuant to the terms of the
Lease.

                               EXHIBIT B - Page 7
<PAGE>   62

                             SCHEDULE 1 TO EXHIBIT B

                                 TIME DEADLINES

<TABLE>
<CAPTION>
          Dates                                Actions to be Performed
          -----                                -----------------------
<S>                                      <C>
1. Day 1                                 "Final Space Plan to be completed by
                                         Tenant and delivered to Landlord.

2. Day 2                                 Architect and Engineers commence
                                         working drawings.

3. Day 42                                Submittal of "Final Working Drawings"
                                         to Tenant and Landlord for approval.

4. Day 48                                Submittal of Tenant and Landlord
                                         approved working drawings to City for
                                         plan check.

5. Day 90                                Estimated date for receipt of all
                                         required permits (8 week review).

6. Day 98                                Cost Proposal to be submitted to Tenant.

7. Day 105                               Tenant to approve Cost Proposal

8. Day 106                               Commencement of Tenant Improvement
                                         construction.

9. Day 162                               Issuance of Temporary Certificate of
                                         Occupancy.
</TABLE>

<PAGE>   63

                                    EXHIBIT C

                           IRVINE OAKS EXECUTIVE PARK

                           NOTICE OF LEASE TERM DATES

To:  _______________________
     _______________________
     _______________________
     _______________________

     Re:   Office Lease dated ___________, 19__ between _______________________,
           a ___________________ ("Landlord"), and
           ________________________________, a ___________________ ("Tenant")
           concerning Suite ______ on floor(s) ________ of the office building
           located at ___________________________________________, Los Angeles,
           California.

        Gentlemen:

        In accordance with the Office Lease (the "Lease"), we wish to advise you
and/or confirm as follows:

        1. The Lease Term shall commence on or has commenced on ___________ for
a term of ______________ ending on ______________.

        2. Rent commenced to accrue on ______________, in the amount of
______________.

        3. If the Lease Commencement Date is other than the first day of the
month, the first billing will contain a pro rata adjustment. Each billing
thereafter, with the exception of the final billing, shall be for the full
amount of the monthly installment as provided for in the Lease.

        4. Your rent checks should be made payable to
_______________________________ at _________________________________.

        5. The exact number of rentable/usable square feet within the Premises
is __________ square feet.

<PAGE>   64

        6. Tenant's Share as adjusted based upon the exact number of usable
square feet within the Premises is _________%.

                                       "Landlord":

                                       ________________________________________,
                                       a _______________________________________

                                       By: _____________________________________

                                       Its: ____________________________________

Agreed to and Accepted
as of ______________, 19__.

"Tenant":

___________________________________________
a _________________________________________

By: _______________________________________

Its: ______________________________________

                               EXHIBIT C - Page 2
<PAGE>   65

                                    EXHIBIT D

                           IRVINE OAKS EXECUTIVE PARK

                              RULES AND REGULATIONS

        Tenant shall faithfully observe and comply with the following Rules and
Regulations. Landlord shall not be responsible to Tenant for the nonperformance
of any of said Rules and Regulations by or otherwise with respect to the acts or
omissions of any other tenants or occupants of the Project. In the event of any
conflict between the Rules and Regulations and the other provisions of this
Lease, the latter shall control.

        1. Tenant shall not alter any lock or install any new or additional
locks or bolts on any doors or windows of the Premises without obtaining
Landlord's prior written consent. Tenant shall bear the cost of any lock changes
or repairs required by Tenant. Two keys will be furnished by Landlord for the
Premises, and any additional keys required by Tenant must be obtained from
Landlord at a reasonable cost to be established by Landlord. Upon the
termination of this Lease, Tenant shall restore to Landlord all keys of stores,
offices, and toilet rooms, either furnished to, or otherwise procured by, Tenant
and in the event of the loss of keys so furnished, Tenant shall pay to Landlord
the cost of replacing same or of changing the lock or locks opened by such lost
key if Landlord shall deem it necessary to make such changes.

        2. All doors opening to public corridors shall be kept closed at all
times except for normal ingress and egress to the Premises.

        3. Landlord reserves the right to close and keep locked all entrance and
exit doors of the Building non-business hours. Tenant, its employees and agents
must be sure that the doors to the Building are securely closed and locked when
leaving the Premises if it is after the normal hours of business for the
Building. In case of invasion, mob, riot, public excitement, or other commotion,
Landlord reserves the right to prevent access to the Building or the Project
during the continuance thereof by any means it deems appropriate for the safety
and protection of life and property.

        4. The requirements of Tenant will be attended to only upon application
at the management office for the Project or at such office location designated
by Landlord. Employees of Landlord shall not perform any work or do anything
outside their regular duties unless under special instructions from Landlord.

        5. No sign, advertisement, notice or handbill shall be exhibited,
distributed, painted or affixed by Tenant on any part of the Premises or the
Building without the prior written consent of the Landlord. Tenant shall not
disturb, solicit, peddle, or canvass any occupant of the Project and shall
cooperate with Landlord and its agents of Landlord to prevent same.

        6. The toilet rooms, urinals, wash bowls and other apparatus shall not
be used for any purpose other than that for which they were constructed, and no
foreign substance of any kind

<PAGE>   66

whatsoever shall be thrown therein. The expense of any breakage, stoppage or
damage resulting from the violation of this rule shall be borne by the tenant
who, or whose servants, employees, agents, visitors or licensees shall have
caused same.

        7. Except for vending machines intended for the sole use of Tenant's
employees and invitees, no vending machine or machines other than fractional
horsepower office machines shall be installed, maintained or operated upon the
Premises without the written consent of Landlord.

        8. Subject to Section 5.3 of this Lease, Tenant shall not use or keep in
or on the Premises, the Building, or the Project any kerosene, gasoline or other
inflammable or combustible fluid, chemical, substance or material.

        9. Tenant shall not without the prior written consent of Landlord use
any method of heating or air conditioning other than that supplied by Landlord.

        10. Tenant shall not use, keep or permit to be used or kept, any foul or
noxious gas or substance in or on the Premises, or permit or allow the Premises
to be occupied or used in a manner offensive or objectionable to Landlord or
other occupants of the Project by reason of noise, odors, or vibrations, or
interfere with other tenants or those having business therein, whether by the
use of any musical instrument, radio, phonograph, or in any other way. Tenant
shall not throw anything out of doors, windows or skylights or down passageways.

        11. Tenant shall not bring into or keep within the Project, the Building
or the Premises any animals, birds, aquariums, or, except in areas designated by
Landlord, bicycles or other vehicles.

        12. No cooking shall be done or permitted on the Premises, nor shall the
Premises be used for the storage of merchandise, for lodging or for any
improper, objectionable or immoral purposes. Notwithstanding the foregoing,
Underwriters' laboratory-approved equipment and microwave ovens may be used in
the Premises for heating food and brewing coffee, tea, hot chocolate and similar
beverages for employees and visitors, provided that such use is in accordance
with all applicable federal, state, county and city laws, codes, ordinances,
rules and regulations.

        13. The Premises shall not be used for manufacturing or for the storage
of merchandise except as such storage may be incidental to the use of the
Premises provided for in the Summary.

        14. Landlord reserves the right to exclude or expel from the Project any
person who, in the judgment of Landlord, is intoxicated or under the influence
of liquor or drugs, or who shall in any manner do any act in violation of any of
these Rules and Regulations.

        15. Tenant, its employees and agents shall not loiter in or on the
entrances, corridors, sidewalks, lobbies, courts, halls, stairways, elevators,
vestibules or any Common Areas for the purpose of smoking tobacco products or
for any other purpose, nor in any way obstruct such areas, and shall use them
only as a means of ingress and egress for the Premises.

                               EXHIBIT D - Page 2
<PAGE>   67

        16. Tenant shall not waste electricity, water or air conditioning and
agrees to cooperate fully with Landlord to ensure the most effective operation
of the Building's heating and air conditioning system, and shall refrain from
attempting to adjust any controls.

        17. Tenant shall store all its trash and garbage within the interior of
the Premises. No material shall be placed in the trash boxes or receptacles if
such material is of such nature that it may not be disposed of in the ordinary
and customary manner of removing and disposing of trash and garbage in Irvine,
California without violation of any law or ordinance governing such disposal.
All trash, garbage and refuse disposal shall be made only through entry-ways and
elevators provided for such purposes at such times as Landlord shall designate.

        18. Tenant shall comply with all safety, fire protection and evacuation
procedures and regulations established by Landlord or any governmental agency.

        19. Any persons employed by Tenant to do janitorial work shall be
subject to the prior written approval of Landlord, and while in the Building and
outside of the Premises, shall be subject to and under the control and direction
of the Building manager (but not as an agent or servant of such manager or of
Landlord), and Tenant shall be responsible for all acts of such persons.

        20. No awnings or other projection shall be attached to the outside
walls of the Building without the prior written consent of Landlord, and no
curtains, blinds, shades or screens shall be attached to or hung in, or used in
connection with, any window or door of the Premises other than Landlord standard
drapes. All electrical ceiling fixtures hung in the Premises or spaces along the
perimeter of the Building must be fluorescent and/or of a quality, type, design
and a warm white bulb color approved in advance in writing by Landlord. Neither
the interior nor exterior of any windows shall be coated or otherwise
sunscreened without the prior written consent of Landlord. Tenant shall abide by
Landlord's regulations concerning the opening and closing of window coverings
which are attached to the windows in the Premises, if any, which have a view of
any interior portion of the Building or Building Common Areas.

        21. The sashes, sash doors, skylights, windows, and doors that reflect
or admit light and air into the halls, passageways or other public places in the
Building shall not be covered or obstructed by Tenant, nor shall any bottles,
parcels or other articles be placed on the windowsills.

        22. Tenant must comply with reasonable requests by the Landlord
concerning the informing of their employees of items of importance to the
Landlord.

        23. Tenant hereby acknowledges that Landlord shall have no obligation to
provide guard service or other security measures for the benefit of the
Premises, the Building or the Project. Tenant hereby assumes all responsibility
for the protection of Tenant and its agents, employees, contractors, invitees
and guests, and the property thereof, from acts of third parties, including
keeping doors locked and other means of entry to the Premises closed, whether or
not Landlord, at its option, elects to provide security protection for the
Project or any portion thereof. Tenant further assumes the risk that any safety
and security devices, services and programs which Landlord elects, in its sole
discretion, to provide may not be effective, or may malfunction or be
circumvented by an

                               EXHIBIT D - Page 3
<PAGE>   68

unauthorized third party, and Tenant shall, in addition to its other insurance
obligations under this Lease, obtain its own insurance coverage to the extent
Tenant desires protection against losses related to such occurrences. Tenant
shall cooperate in any reasonable safety or security program developed by
Landlord or required by law.

        24. All office equipment of any electrical or mechanical nature shall be
placed by Tenant in the Premises in settings reasonably approved by Landlord, to
absorb or prevent any unreasonable vibration, noise and annoyance.

        25. Tenant shall not use in any space or in the public halls of the
Building, any hand trucks except those equipped with rubber tires and rubber
side guards.

        26. No auction, liquidation, fire sale, going-out-of-business or
bankruptcy sale shall be conducted in the Premises without the prior written
consent of Landlord.

        27. No tenant shall use or permit the use of any portion of the Premises
for living quarters, sleeping apartments or lodging rooms.

        Landlord reserves the right at any time to change or rescind any one or
more of these Rules and Regulations, or to make such other and further
reasonable Rules and Regulations as in Landlord's judgment may from time to time
be necessary for the management, safety, care and cleanliness of the Premises,
Building, the Common Areas and the Project, and for the preservation of good
order therein, as well as for the convenience of other occupants and tenants
therein. Landlord may waive any one or more of these Rules and Regulations for
the benefit of any particular tenants, but no such waiver by Landlord shall be
construed as a waiver of such Rules and Regulations in favor of any other
tenant, nor prevent Landlord from thereafter enforcing any such Rules or
Regulations against any or all tenants of the Project. Tenant shall be deemed to
have read these Rules and Regulations and to have agreed to abide by them as a
condition of its occupancy of the Premises.

                               EXHIBIT D - Page 4
<PAGE>   69

                                    EXHIBIT E

                           IRVINE OAKS EXECUTIVE PARK

                      FORM OF TENANT'S ESTOPPEL CERTIFICATE

        The undersigned as Tenant under that certain Office Lease (the "Lease")
made and entered into as of ____________, 199_ by and between
___________________ as Landlord, and the undersigned as Tenant, for Premises on
the ____________ floor(s) of the office building located at ___________________,
Irvine, California ____________, certifies as follows:

        1. Attached hereto as Exhibit A is a true and correct copy of the Lease
and all amendments and modifications thereto. The documents contained in Exhibit
A represent the entire agreement between the parties as to the Premises.

        2. The undersigned currently occupies the Premises described in the
Lease, the Lease Term commenced on ____________, and the Lease Term expires on
____________.

        3. Base Rent became payable on ____________.

        4. The Lease is in full force and effect and has not been modified,
supplemented or amended in any way except as provided in Exhibit A.

        5. Tenant has not transferred, assigned, or sublet any portion of the
Premises nor entered into any license or concession agreements with respect
thereto except as follows:

        6. Tenant shall not modify the documents contained in Exhibit A without
the prior written consent of Landlord's mortgagee.

        7. All monthly installments of Base Rent, all Additional Rent and all
monthly installments of estimated Additional Rent have been paid when due
through ____________. The current monthly installment of Base Rent is
$_______________.

        8. To Tenant's current actual knowledge, all conditions of the Lease to
be performed by Landlord necessary to the enforceability of the Lease have been
satisfied and Landlord is not in default thereunder.

        9. No rental has been paid more than thirty (30) days in advance and no
security has been deposited with Landlord except as provided in the Lease.

<PAGE>   70

        10. To Tenant's current actual knowledge, as of the date hereof, there
are no existing defenses or offsets that the undersigned has against Landlord.

        11. If Tenant is a corporation or partnership, each individual executing
this Estoppel Certificate on behalf of Tenant hereby represents and warrants
that Tenant is a duly formed and existing entity qualified to do business in
California and that Tenant has full right and authority to execute and deliver
this Estoppel Certificate and that each person signing on behalf of Tenant is
authorized to do so.

        The undersigned acknowledges that this Estoppel Certificate may be
delivered to Landlord or to a prospective mortgagee or prospective purchaser,
and acknowledges that said prospective mortgagee or prospective purchaser will
be relying upon the statements contained herein in making the loan or acquiring
the property of which the Premises are a part and that receipt by it of this
certificate is a condition of making such loan or acquiring such property.

        Executed at ___________________ on the ________ day of 19__.

                                       "Tenant":

                                       ________________________________________,
                                       a _______________________________________

                                       By: _____________________________________
                                            Its: _______________________________

                                       By: _____________________________________
                                            Its: _______________________________

                               EXHIBIT E - Page 2
<PAGE>   71

                                    EXHIBIT F

                          JANITORIAL SERVICE STANDARDS

SECTION 7  Tenanted Areas

7-01     DAILY Secure all lighting as soon as possible. Illuminate only the
         immediate work area as required.

7-02     DAILY Police all stairwells, remove all debris and obstructions. Sweep,
         dust mop and damp mop as required.

7-03     DAILY Clean/polish all glass doors, glass partitions and framing to
         a bright condition, free of dust and streaks.

7-04     DAILY Dust wipe, with treated cloth, all horizontal surfaces within
         reach, including ledges, sills, molding and furniture tops, sides,
         legs and glass coverings. Spot clean as necessary. All papers and
         folders left on desks and cabinets will not be removed.

7-05     DAILY  Clean/sanitize all telephone receivers.

7-06     DAILY Spot clean all vertical surfaces, brightwork and fixtures to
         remove graffiti and soil, with special attention near switchplates,
         waste receptacles, cigarette urns, door handles and frames.

7-07     DAILY Clean all chalkboards/message boards and/or trays except
         where written text has not been erased by tenant.

7-08     DAILY  Clean/sanitize and polish all drinking fountains.

7-09     DAILY Police all interior planters, remove debris and spot clean
         exterior surfaces as necessary.

7-10     DAILY Empty and clean all waste receptacles, cigarette urns and
         ashtrays. Remove all trash to designated trash area, replace trash
         liners and water or sand as appropriate for cigarette urns.

7-11     DAILY  Brush/vacuum all upholstered furniture as necessary.

7-12     DAILY Vacuum all carpeted floors/mats, moving light furniture such
         as chairs, waste receptacles and urns. Vacuum under all desks,
         large furniture and along base of all vertical surfaces where
         possible. Spot clean carpeting of soils as necessary.

<PAGE>   72

7-13     DAILY Dust mop all hard surface floors with a treated dust mop,
         moving light furniture where possible. Dust mop under all desks and
         large furniture where possible. Hard surface floors shall be spot
         cleaned, wet mopped and spray buffed as necessary to remove soil,
         scuff marks and preserve the floor finish.

7-14     DAILY Replace all furniture and/or accessories moved to accommodate
         cleaning to original position.

7-15     DAILY Remove all refuse to the designated retention or trash area, as
         appropriate.

7-16     MONTHLY Dust all high reach areas and fixtures beyond reach for daily
         dusting.

7-17     MONTHLY Brush/vacuum all wall and ceiling vents and grills.

7-18     MONTHLY Recondition all hard surface floors and vinyl base to
         provide a level of appearance equivalent to a completely refinished
         floor. All wax marks shall be removed from walls, doors and frames.

7-19     QUARTERLY Wipe clean 1/4 of all light fixture covers, scheduled to
         include all fixtures annually.

                               EXHIBIT F - Page 2
<PAGE>   73

TENANT IMPROVEMENT STANDARDS
IRVINE OAKS EXECUTIVE PARK

DEMISING PARTITION

         a.  3 5/8" - 25 gauge metal studs - 16" on center.

         b.  5/8" drywall type "x" one layer tenant side only.

         c.  Height from floor slab to structure above.

         d.  Partition taped smooth to receive paint.

         e.  Batt insulation in cavity, R-11 to underside of structure.

INTERIOR PARTITION OFFICE

         a.  2-1/2" - 25 gauge studs - 24" on center.

         b.  5/8" drywall - one layer each side of studs.

         c.  Height from floor slab to ceiling above.

         d.  Partition taped smooth to receive paint to underside of suspended
             ceiling.

         e.  Neoprene gasket at exterior glazing.

INTERIOR DOOR ASSEMBLY

         a.  Door - 3'0" x 8'0"x 1-3/4" solid core, plain sliced red oak
             veneer with matching edge band.

         b.  Frame - 3'0" x 8'0" "TIMELY" black factory painted. Throat
             size to fit wall.

         c.  Latch set - Schlage -Rhodes 10-S 625 lever with matching
             strike finish to match existing.

         d.  Hinges - RC 700 4 x 4 x 625 Hagar or equal (4 per door).

         e. Stop - Builders Brass Works #8061 with riser or equal (Floor Stop).

RATED DOOR ASSEMBLIES

         a.  Door - 3'0"x 8'0"x 1-3/4" solid core (20 min label) plain
             sliced red oak veneer/matching edge band.

         b.  Frame - 3'0"x8'0" "TIMELY", 20 minute rated, Black factory
             painted. Throat size to fit wall.

         c.  Lock set - Schlage Rhodes D-53 625 lever " " key way with matching
             strike.

         d.  Closer - 4010N x cover x al arm LCN or equal

         e.  Hinges - BB RC 700 4x4x625 Hagar or equal.

         f.  Door Stop - Builders Brass Works #8061 with riser or equal (Floor
             Stop).

         g.  Astrigals - Pemco 355 alm finish.  (At pair of doors)

         h.  Dust proof strikes - D.P.2 Glenn Johnson (At pair of doors)

         i.  Flush Bolts FB8- Glenn Johnson (At pair of doors)

<PAGE>   74

ACOUSTICAL CEILING

         a.  2'x2' Donn Meridian intermediate duty T-Bar suspension system,
             matte white finish, at approximately 9'-0" AFF.

         b.  2'x2' USG. Auratone #344 "Omni Fissured" 5/8" with grid edge,
             lay-in type with shoulder flush with grid.

         c.  Wire suspension per code.

FIRE SPRINKLERS

         a.  Semi-recessed head, with flush-mounted chrome escutcheon.

         b.  Drop heads from existing distribution, relocate as required.

         c.  Engineering as required.

         d.  Concealed white escutcheons at drywall ceilings.

FLOOR COVERING

         a.  Carpet - Designweave, "New Temptest" (32 oz cut pile) direct glue.
             Alternate - Designweave, "Alumni" (28 oz loop pile) direct glue.

         b.  Vinyl Composition Tile (VCT) "Armstrong" Imperial Texture 12" x 12"
             x 1/8".

RUBBER TOPSET BASE

         a.  4" Rubber topset base, Burke.

         b.  Any standard commercial color.

PAINTING

         a.  Two coats flat interior latex paint.

         b.  Doors stain and lacquer.

EXIT SIGNS

         "MARCO" universal exit sign with battery pack, white housing with green
letters, ceiling mounted.

WINDOW COVERING

         a.  1" aluminum mini-blinds - Levelor "Riviera," white (or equal).
             All exterior building glazing throughout office area.

TENANT SIGNAGE

         Signage to be provided by Tenant pursuant to the Project Sign Criteria.

H.V.A.C.

                                       2
<PAGE>   75

         a.  Supply registers - Kruger 6500 series, white to match T-bar.

         b.  Thermostats - Honeywell T-7300 programmable

2' X 4' FLOURESCENT LIGHT FIXTURE

         a.  2' x 4' "Lithonia" lay-in type, 2GT-332-A12-(120V/277V)-GEB-LST.
             (3) Fo32-T8 lamps, with electronic ballast, prismatic lens or
             approved equal.

         b.  Wire suspension per code.

         c.  Switching per Title 24.

         d.  Design and engineer electrical per Title 24.

         e.  Connect one fixture per 2,000 sq. ft. to emergency lighting system.

8' FLOURESCENT LIGHT FIXTURE - WAREHOUSE

         a.  8' "Lithonia", EJA-296-PG 120/277 ES, 2F96 cool white lamps.

         b.  Wire suspension per code.

         c.  Switching per Title 24.

         d.  Design and engineer electrical per Title 24.

         e.  Connect one fixture per 2,000 sq. ft. to emergency lighting system.

LIGHT SWITCH ASSEMBLY

         a.  "Levitron," Decora, #5600 Series, or equal, white toggle and cover
             plate.

         b.  Switches paired in double gang box per Title 24 requirements.
             (California)

         c.  Mounted 42" AFF, to center of switch.

ELECTRICAL WALL OUTLET

         a.  "Levitron," #5600-sw or equal, duplex receptacle, 1 each - white
             receptacle and cover plate

         b.  Mounted vertically.

         c.  Outlet height at 15" AFF to underside of outlet.

         d.  Design and engineer electrical per Title 24. (California)

TELEPHONE WALL OUTLET

         a.  Single gang box in wall - mounted vertically at 15" AFF to
             underside of box.

         b.  3/4" metal conduit up wall stubbed 6" above ceiling.

         c.  With pull string and ring.

         d.  Cover plate by Tenant's telephone company.

                                       3
<PAGE>   76

                           IRVINE OAKS EXECUTIVE PARK

                           NOTICE OF LEASE TERM DATES

TO:      GADZOOX NETWORKS, INC.
         16241 Laguna Canyon Road, Suite 100
         Irvine, CA  92618

         Re:      Office Lease dated October 1999, between IRVINE OAKS REALTY
                  HOLDING COMPANY, a Delaware Corporation ("Landlord"), and
                  GADZOOX NETWORKS, INC., a Delaware corporation ("Tenant")
                  concerning Suite 100, on floor(s) one of the building located
                  at 16241 Laguna Canyon Road, Irvine, California.

Gentlemen:

         In accordance with the Office Lease (the "Lease"), we wish to advise
you and/or confirm as follows:

         1. Tenant has accepted the premises per Article 2 of the Office Lease
dated November 17, 1999, subject to the following punch list dated March 27,
2000.

         2. The Lease Term shall commence on or has commenced on March 16, 2000
for a term of sixty-one (61) months ending on April 15, 2005.

         3. Rent commenced to accrue on March 16, 2000, in the amount of
$21,987.28 per month. Tenant shall not be required to pay any Base Rent
attributable to the first month of the Lease Term.

         4. If the Lease Commencement Date is other than the first day of the
month, the first billing will contain a pro rata adjustment. Each billing
thereafter, with the exception of the final billing, shall be for the full
amount of the monthly installment as provided for in the Lease.

         5. Your rent check should be made payable to IRVINE OAKS REALTY HOLDING
            COMPANY at:

                           Irvine Oaks Realty Holding Co., Inc.
                           c/o SARES- REGIS Group
                           P.O. Box 41127
                           Santa Ana, CA  92799-1127

         6. The exact number of rentable square feet per the Lease is 14,133
square feet.

<PAGE>   77

         7. Tenant's Project Share as adjusted based upon the exact number of
rentable square feet within the Premises is 4.37% per the Lease, Tenant's
Building Share as adjusted based upon the exact number of rentable square feet
within the Premises is 33.24%.

                                       "Landlord":

                                       IRVINE OAKS REALTY HOLDING CO, INC. a
                                       Delaware corporation

                                       By: _____________________________________
                                          Its:  ________________________________

Agreed to and Accepted
As of ______________________________.

"Tenant":

____________________________________
a __________________________________

By: ________________________________
   Its:  ___________________________

                                       2

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