<PAGE>
                                                                   EXHIBIT 10.73

                                    SUBLEASE

                  THIS SUBLEASE (this "Sublease") is dated for reference
purposes as of December 12, 2002, and is made by and between Copper Dragon Books
a California corporation ("Sublessee"); and MTI, a Delaware corporation
("Sublessor").

                                   RECITALS:

                  This Sublease is made with reference to the following facts:

                  A.       Westport Joint Venture, a California joint venture,
                           as landlord (the landlord under the Master Lease is
                           herein called the "Master Lessor"), and MTI, Inc., a
                           California corporation, as tenant, entered into that
                           certain Lease Agreement, dated as of June 15, 2001
                           (the "Master Lease") with respect to a portion of
                           that certain one story office building located at 474
                           Potrero Drive, Sunnyvale California. A true, correct
                           and complete copy of the Master Lease is attached
                           hereto as Exhibit "A" and incorporated by reference
                           herein. Sublessor is currently the original tenant
                           under the Master Lease.

                  B.       Pursuant to the Master Lease, the Premises leased
                           thereunder encompasses approximately 2700 square feet
                           (a portion of the entire facility at 474 Potrero
                           Avenue, Sunnyvale, which consists of approximately
                           22,000+/- square feet.

                  C.       Sublessee wishes to sublease the Premises. Sublessor
wishes to sublease the Premises to Sublessee on the terms and conditions
contained herein.

                  Accordingly, in consideration of the mutual promises contained
herein and for other good and valuable consideration, receipt of which is hereby
acknowledged, the parties hereto agree as follows:

                  1.       Premises: Subject to the condition precedent
contained in Section 10, below, Sublessor hereby subleases to Sublessee, and
Sublessee hereby subleases from Sublessor the Premises on the terms and
conditions contained herein. All capitalized terms in this Sublease shall have
the meaning ascribed to them in the Master Lease unless otherwise defined
herein.

                  2.       Term:

                           2.1      Term: The term (the "Term") of this Sublease
shall be for a period commencing on January 16, 2003, and Sublessor has
delivered possession of the Premises to Sublessee (the "Commencement Date"). The
Term shall end, without notice, on June 14, 2006 (the "Expiration Date"), unless
this Sublease is sooner terminated pursuant to its terms or unless the Master
Lease is sooner terminated pursuant to its terms. If for any reason the
Commencement Date has not occurred on or before January 16, 2003, then this
Sublease shall automatically be void and of no force or effect. On any such
termination, neither Sublessor nor


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Sublessee shall have any rights against or obligations to the other, provided
that Sublessor shall return to Sublessee any monies previously paid by Sublessee
to Sublessor hereunder.

                           2.2      No Option to Extend: Sublessee hereby
acknowledges that: (i) the expiration date of the Master Lease is June 14, 2006,
(ii) Sublessor has no option whatsoever to extend the Term of the Master Lease,
and (iii) Sublessee must vacate the Premises fully and completely on or before
June 14, 2006.

                  3.       Rent:

                           3.1      Base Rent: Sublessee shall pay to Sublessor
the rent ("Base Rent") for the Premises in the following amounts:

<TABLE>
<CAPTION>
                 Months          Amount
                 ------        ----------
                 <S>           <C>
                  1-12         $(1,500.00)
                 13-24         $(1,545.00)
                 25-36         $(1,591.35)
                 37-41         $(1,639.09)
</TABLE>

Sublessor and Sublessee agree that for all purposes under this Sublease, the
Premises contains approximately Two Thousand Seven Hundred (2,700) square feet
of rentable area. Base Rent shall be paid in advance prior to occupancy.

                           3.2      Additional Rent: This Sublease is a Gross
lease and it is the intent of the parties hereto that Sublessee shall have no
costs, expenses or payments whatsoever in connection with the Premises or the
Master Lease, and that all such costs, expenses and payments shall be the
responsibility of Sublessor including utilities. Sublessee shall be responsible
for Janitorial.

                  4.       Master Lease:

                           4.1      Incorporation of Master Lease: The terms,
conditions and respective obligations of Sublessor and Sublessee to each other
under this Sublease shall be the terms of the Master Lease, except as modified
in this Section 4, or as otherwise set forth in this Sublease, and except that:
(a) wherever in the Master Lease the word "Tenant" appears, for the purposes of
this Sublease, the word "Sublessee" shall be substituted; (b) wherever in the
Master Lease the word "Lease" appears, for the purposes of this Sublease, the
word "Sublease" shall be substituted; and (c) wherever in the Master Lease the
word "Landlord" appears, for the purposes of this Sublease, the word "Sublessor"
shall be substituted. Sublessee hereby acknowledges that


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it has read and is familiar with the terms of the Master Lease and agrees that
this Sublease is subordinate and subject to the Master Lease, and that any
termination of the Master Lease shall likewise terminate this Sublease.

                                    Termination of Master Lease: If Master
Lessor and Sublessor jointly and voluntarily elect, for any reason whatsoever,
to terminate the Master Lease prior to the scheduled Master Lease termination
date, then this Sublease (if then still in effect) shall terminate concurrently
with the termination of the Master Lease given 30 days written notice. In the
event of the Master Lease termination, Sublessee shall be compensated by
Sublessor the unused portion of prepaid rental.

                           4.2      Time Allowances: Consents: With respect to
any obligation of Sublessee to be performed under this Sublease, wherever the
Master Lease grants to Sublessor a specified number of days to perform its
obligations under the Master Lease, except as otherwise provided herein,
Sublessee shall have the same number of days to perform the obligation,
including, without limitation, curing any defaults.

                           4.3      Use: Sublessee may use the Premises only for
those uses permitted under the Master Lease, and in no event for any use
prohibited or restricted by the Master Lease or by law. Sublessee shall not
commit or permit to be committed on the Premises any act or omissions which
shall violate any term or condition of the Master Lease.

                  5.       Right to Cure Defaults:

                           5.1      Sublessee's Rights: If Sublessor fails to
perform any act on its part to be performed by Sublessor hereunder, then
Sublessee may, but shall not be obligated to, after thirty (30) days after the
date of Sublessee's written notice to Sublessor identifying the failure, and
after the passage of any notice and cure periods, and subject to the terms of
the Master Lease, perform such act. All such sums paid, and all reasonable costs
and expenses of performing any such act, shall be payable promptly by Sublessor
to Sublessee, together with interest thereon at the Interest Rate from the date
of the expenditure until repaid.


                                      -3-

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                  6.       Deposit: Sublessee shall pay Sublessor a security
deposit in the amount of $1,500.00 upon execution of this Sublease agreement.

                  7.       Broker: Sublessor and Sublessee each represent to the
other that they have dealt with no real estate brokers other than Vandermade.
Each party agrees to hold the other party harmless from and against all claims
for brokerage commissions, finder's fees or other compensation made by any other
agent, broker, salesman or finder as a consequence of said party's actions or
dealings with such agent, broker, salesman, or finder.

                  8.       Authority to Execute: Sublessee and Sublessor each
represent and warrant to the other that each person executing this Sublease on
behalf of each party is duly authorized to execute and deliver this Sublease on
behalf of that party.

                  9.       Intentionally Deleted.

                  10.      Intentionally Deleted

                  11.      As-Is:

                           11.1     No Warranties: Sublessor has made no
representations or warranties of any kind, whether express or implied, as to the
condition of the Premises, the Building, the Complex or any other property, or
the suitability of the Premises for Sublessee's activities. Sublessee
acknowledges that prior to signing this Sublease, it has had the opportunity to
inspect and research the Building and the Premises, and to contact the Master
Lessor in order to independently satisfy itself as to the condition of same,
including without limitation, the presence or absence of Hazardous Materials.
Sublessee enters and agrees to use the Premises at its own risk, "as is", and
subject to any defects (whether patent or latent, known or unknown). Sublessee
waives and disclaims all warranties with respect to the Premises and the
Building and the Complex, whether express or implied, and assumes the risk that
its inspections and inquiry of the Master Lessor did not reveal adverse or
unexpected conditions.

                  12.      Sublease and Assignment: Pursuant to the restrictions
of the Master Lease, Sublessee may not sublease or assign all or any portion of
this Sublease. Any such Sublease or assignment shall be null, void and of no
force or effect. Sublessor and Sublessee acknowledge that this prohibition on
subleasing and assignment is required specifically by Master Lessor. Sublessor
and Sublessee recognize the difficulties that such a prohibition by Master
Lessor could cause if Sublessee desires to consolidate or merge. Therefore, if:
there shall occur (1) any assignment, merger or consolidation or other
reorganization of or affecting Sublessee and if Sublessee is not the surviving
corporation; or (2) any involuntary assignment or sublease by reason of
corporate reorganization, assignment, merger, consolidation, or for any other
reason, then unless Master Lessor's and Sublessor's advance written consents are
obtained (which consents may be withheld at their sole discretions), then this
Sublease shall terminate on the occurrence of any of the foregoing events.

                  13.      Furniture: The Premises shall be delivered to
Sublessee with the assets listed on Exhibit "B" attached hereto. During the
Sublease Term, none of the assets listed on


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Exhibit "B" may be removed by Sublessee from the Premises at any time and at the
end of the term said assets shall be delivered by Sublessee to Sublessor in the
condition in which they were delivered to Sublessee, reasonable wear and tear
excepted.

                  14.      Surrender: Notwithstanding the incorporation of
Section 8 of the Master Lease, on expiration of the Term of this Sublease, or on
any other termination of this Sublease, Sublessee shall not be required to
remove any tenant improvements in or alterations to the Premises that were
installed in the Premises prior to the Commencement Date.

                  15.      Termination Payment. If Master Lessor and Sublessor
jointly and voluntarily elect to terminate the Master Lease and this Sublease as
described in Section 4.2, above, then as of the termination, then Sublessor
shall pay to Sublessee a termination payment equal to the unused rental as of
the date of termination. If the Master Lease is terminated by reason of
Sublessor's breach thereof, and if such breach is in no way related to or
connected with a breach of this Sublease by Sublessee, and if after Master Lease
termination the Master Lessor requires Sublessee to continue its tenancy under
this Sublease at the Basic Rent paid by Sublessor under the Master Lease, then
Sublessor shall pay to Master Lessor on a monthly basis, as and when due, the
difference between the Basic Rent under the Master Lease and the Base Rent under
this Sublease for the remaining term of this Sublease (or if earlier, its
termination for any reason).

                  16.      Miscellaneous:

                           16.1     Entire Sublease; Amendment: This Sublease
(which includes all exhibits hereto) embodies the entire Sublease and
understanding between the parties relating to the subject matter hereof, and all
prior negotiations, agreements and understandings, oral or written, are hereby
revoked, cancelled and rescinded and are all merged herein and superseded
hereby. Any amendment to this Sublease, including, without limitation, any oral
modification supported by new consideration, must be reduced to writing and
signed by both parties in order to be effective.

                           16.2     Counterparts; Waiver: This Sublease may be
executed in two or more counterparts, each of which shall be deemed to be an
original, but all of which together shall constitute one and the same
instrument. Any waiver of the performance of any covenant, condition or promise
by either party, in order to be effective, must be in a writing signed by the
party who has allegedly waived the covenant, condition or promise in question.

                           16.3     Severability: Should any part, term or
provision of this Sublease or any document required herein to be executed or
delivered be declared invalid, void or unenforceable, all remaining parts, terms
and provisions hereof shall remain in full force and effect and shall in no way
be invalidated, impaired or affected thereby.

                           16.4     Interpretation: The neuter gender includes
the feminine and masculine, and vice-versa, and the singular number includes the
plural. The word "person" includes, in addition to any natural person, a
corporation, partnership, firm, trust, association, governmental body or other
entity. Whether expressly stated or not in this Sublease, any


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indemnification, release, waiver, hold harmless, covenant to protect or covenant
to defend made in this Sublease by one party in favor of the other party shall
benefit not only such other party but each and all of its officers, directors,
agents, employees, successors and assigns. The captions of the sections of this
Sublease are for convenience and reference only, and the words contained therein
shall in no way be held to explain, modify, or aid in the interpretation,
construction or meaning of the provisions of this Sublease.

                           16.5     Attorneys' Fees: In the event that any suit
in law or equity, arbitration or other formal proceeding is instituted by either
party to enforce or interpret any part of this Sublease, or to recover damages
for breach thereof, the prevailing party shall be entitled to recover costs of
suit incurred therein, and to also recover as an element of such costs (or as
damages, only if not allowed as costs), a reasonable attorney fee to be fixed by
the presiding tribunal. A party not entitled to recover costs shall not recover
attorney fees. No sum of attorney fees shall be included in any computation of
the amount of judgment or award for purposes of determining whether a party is
entitled to recover costs of attorney fees.

                           16.6     Construction: The parties hereto agree that
each party and its counsel or advisor have reviewed and revised this Sublease
and that any rule of construction to the effect that ambiguities are to be
resolved against the drafting party shall not apply in the interpretation of
this Sublease or any amendments or exhibits hereto.

                           16.7     Notice: Any notice, demand, request,
consent, approval, or communication that either party desires or is required to
give to the other party or any other person shall be in writing and served
personally, sent by certified first-class mail, return receipt requested or sent
by a commercial overnight courier service (e.g. FedEx). Any notice, demand,
request, consent, approval or communication that either party desires or is
required to give to the other party shall be addressed to the other party at the
address set forth below:

                           If to Sublessee:

                                    Prior to Commencement Date:

                                    Copper Dragon Books
                                    1435 The Alameda
                                    San Jose, CA 95126
                                    Attn: Mark Anderson

                                    After Commencement Date:

                                    Copper Dragon Rooks
                                    474 Potrero Avenue
                                    Sunnyvale, CA 94086
                                    Attn: Ahmed Alali


                                    If to Sublessor:


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<PAGE>

                                    MTI Corporation
                                    4905 E. La Palma Avenue
                                    Anaheim, CA 92807

Either party may change its address by notifying the other party of the change
of address. Notices shall be effective when received or refused, as evidenced by
return receipt or courier's receipt slip.

                           16.8     Limitation of Liability: No personal
liability or personal responsibility is assumed by, or shall at any time be
asserted or enforceable against, Sublessor's or Sublessee's respective
directors, officers, employees, consultants or advisors on account of this
Sublease or on account of any covenant, undertaking or agreement of Sublessor or
Sublessee contained in this Sublease.

                           16.9     Sublessor's Covenants: Notwithstanding
anything to the contrary in this Sublease, so long as Sublessee is not in
default under this Sublease, Sublessor shall: (1) not modify, amend or waive any
provisions thereof or make any election, exercise any option, right or remedy,
or grant any consent or approval thereunder which would affect Sublessee's
interests under this Sublease without, in each instance, Sublessee's prior
written consent; and (2) pay the rent due and perform all of Sublessor's
obligations under the Master Lease, except to the extent that Sublessee is
obligated to perform such obligations under this Sublease. Sublessor shall (a)
upon Sublessee's written request, notify Master Lessor of its nonperformance
under the Master Lease and request that Master Lessor perform its obligations
under the Master Lease.

                           16.10    Sublessor's Representations and Warranties:
Sublessor represents and warrants that to the best of its actual knowledge as of
Sublessor's signing of this Sublease: (i) the Master Lease is in full force and
effect, and that it has received no written notice that there exists under the
Master Lease any default or event of default by either Master Lessor or
Sublessor or that there has occurred any event which, with the giving of notice
or the passage of time or both, could constitute such a default or event of
default; and (ii) it has received no written notice of any pending or threatened
actions, suits or proceedings before any court or administrative agency against
Sublessor, Master Lessor or third parties which could, in the aggregate,
adversely affect the Premises or any part thereof or the ability of Master
Lessor or Sublessor to perform their respective obligations under the Master
Lease or of Sublessor to perform its obligations under the Sublease and (iii) in
all material respects, a true correct and complete copy of the Master Lease is
attached hereto as Exhibit A. As used in this Section 17.10, Sublessor's "actual
knowledge" shall mean the conscious knowledge of Frank Pedraza, in-house real
estate counsel for Sublessor, with no duty to investigate.


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                  IN WITNESS WHEREOF, the parties have executed this Sublease as
of the day and year first above written.



SUBLESSEE:                             Copper Dragon Books., a California
                                       corporation



                                       By: /s/ Mark Anderson
                                          --------------------------------------

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



SUBLESSOR:                             MTI, a California corporation



                                       By: /s/ Mark A. Franzen
                                          --------------------------------------
                                          Mark A. Franzen
                                       Its: Chief Financial Officer
                                           -------------------------------------


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<PAGE>

                              ADDENDUM TO SUBLEASE

         This addendum to the sublease dated 12/23/02 made by and between Copper
Dragon Books a ___________ corporation, hereinafter referred to as the
("Sublessee") and MTI Technologies, Corporation, a Delaware Corporation
hereinafter referred to as the ("Sublessor").

                                    Whereas:

         3. Rent

         The rent is due on or before the 16th day of each month. A six percent
(6%) Late payment penalty will be charged for any rental payment that is not
received within five (5) working days from the date the rent is due. This
includes any additional amounts that may become due under 3.2 of this agreement.

         3.2 Additional Rent:

         The Sublease is a Gross lease with the additional exception. Sublessee
shall be responsible for it's prorated share of the utility cost for electricity
over the allowed building usage of $4,133 per month. Any usage above this base
amount will be charged on a quarterly basis to the Sublessee in the amount equal
to 10% percent of the total billings above the base amount charged to the
Sublessor by the utility company.

         Sublessee shall have the right on any twelve month basis to audit at
it's own expense the utility costs for electricity for the entire building and
it's prorated share should Sublessee so choose to do so. Sublessor agrees to
make these records available upon the Sublessee's written request within fifteen
(15) working days at it's offices in Anaheim or wherever the home office of the
corporation may be at the time the demand for records is made.

         IN WITNESS WHEREOF, the parties have executed this addition to the
original Sublease and it has become a part thereof as of the day and year first
above written.



  SUBLESSEE:                           /s/ Mark Anderson
                                       -----------------------------------------
                                       By:
                                          --------------------------------------
                                      Its:
                                          --------------------------------------



SUBLESSOR:                             MTI Technologies, Corporation



                                       By: /s/ Mark A. Franzen
                                          --------------------------------------
                                       Its: Chief Financial Officer

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[FLOOR PLAN]