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                                                                   EXHIBIT 10.56

                FIRST AMENDMENT TO STOCK RESTRICTION AGREEMENT
                ----------------------------------------------

          THIS FIRST AMENDMENT TO STOCK RESTRICTION AGREEMENT (this "Amendment")
                                                                     ---------
is made as of March 23, 2000, between ZEFER Corp., a Delaware corporation (the
"Company"), and David Lubin ("Holder").  Except as otherwise indicated herein,
 -------                      ------
capitalized terms used and not otherwise defined herein shall have the meanings
ascribed to such terms in the Purchase Agreement (as defined below).

          WHEREAS, the parties to this Amendment are all of the parties to that
certain Stock Restriction Agreement, dated as of March 23, 1999, between the
Company and Holder (the "Stock Restriction Agreement");
                         ---------------------------
          WHEREAS, the parties hereto desire to make certain amendments to the
Purchase Agreement in accordance with Section 12(i) thereof; and

          NOW, THEREFORE, for good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the parties hereto agree as
follows:

Section 1.  Amendments to Stock Restriction Agreement.
            -----------------------------------------

       1A.  Section 2(a) of the Stock Restriction Agreement shall be amended and
restated in its entirety as follows:

            (a)  All of the shares of Holder Stock acquired hereunder shall be
     subject to vesting in the manner specified in this Section 2. Except as
     otherwise provided in Sections 2(b) and 2(c) below, commencing on the day
     immediately following the Closing and continuing so long as Holder is still
     serving as a director of the Company or any of its Subsidiaries,
     the Holder Stock will vest daily on a pro rata basis so that 100% of the
     Holder Stock will be vested on the 5th Anniversary of the Closing (the
     "Vesting Schedule").
      ----------------

       1B.  Section 2(b) of the Stock Restriction Agreement shall be amended and
     restated in its entirety as follows:

            (b)  In the event the Company consummates its initial Public
     Offering prior to the 1st Anniversary of the Closing, the Vesting Schedule
     shall be modified such that, so long as Holder is still serving as a
     director of the Company or any of its Subsidiaries, the shares
     of Holder Stock will vest as follows: (i) 33% of the Holder Stock will vest
     upon the occurrence of such Public Offering, and (ii) commencing on the day
     immediately following such Public Offering, the remaining unvested shares
     of Holder Stock will vest daily on a pro rata basis so that 100% of the
     Holder Stock will be vested on the 5th Anniversary of the Closing. In the
     event the Company consummates its initial Public Offering after the 1st
     Anniversary of the Closing but prior to the 2nd Anniversary of the Closing,
     the Vesting Schedule shall be modified such that, so long as Holder is
     still serving as a director of the Company or any of its Subsidiaries, the
     shares of Holder Stock that are unvested immediately prior to such initial
     Public Offering will vest as follows: (i) an additional number of shares of
     Holder
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     Stock will vest upon the occurrence of such Public Offering so that 33% of
     the Holder Stock will be vested immediately thereafter, (ii) commencing on
     the day immediately following such Public Offering and continuing until the
     2nd Anniversary of the Closing, an additional number of shares of Holder
     Stock will vest daily on a pro rata basis so that 40% of the Holder Stock
     will be vested on the 2nd Anniversary of the Closing, and (iii) commencing
     on the day immediately following the 2nd Anniversary of the Closing, the
     remaining unvested shares of Holder Stock will vest daily on a pro rata
     basis so that100% of the Holder Stock will be vested on the 5th Anniversary
     of the Closing.

            Section 2.  Retroactive Application of Amended and Restated Vesting
                        -------------------------------------------------------
Schedule. The amendment set forth in Section 1A above shall be applied
---------
retroactively so as to cause the Holder Stock to be subject to the amended and
restated Vesting Schedule as of May 21, 1999.

            Section 3.  Limitations.  Except as expressly amended by this
                        ------------
Amendment, all of the terms and provisions of the Stock Restriction Agreement
shall remain in full force and effect. This Amendment supersedes and preempts
any prior understandings, agreements or representations by or between the
parties, written or oral, which may have related to the subject matter hereof in
any way.

                                   *  *  *  *

                                       2
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          IN WITNESS WHEREOF, the parties hereto have executed this First
Amendment to Stock Restriction Agreement on the date first written above.

                                        ZEFER Corp.
                                        By:  /s/ James Slamp
                                            -----------------------------------
                                        Its:  President
                                             /s/ David Lubin
                                            -----------------------------------
                                              David Lubin

Agreed and Accepted:

GTCR FUND VI, L.P.
By:       GTCR Partners VI, L.P.
Its:      General Partner
By:       GTCR Golder Rauner, L.L.C.
Its:      General Partner

By:       /s/ Philip Canfield
     ----------------------------------------
Name:
     ----------------------------------------
Its:      Principal

GTCR VI EXECUTIVE FUND, L.P.
By:       GTCR Partners VI, L.P.
Its:      General Partner
By:       GTCR Golder Rauner, L.L.C.
Its:      General Partner

By:       /s/ Philip Canfield
     ----------------------------------------
Name:
     ----------------------------------------
Its:      Principal

GTCR ASSOCIATES VI
By:       GTCR Partners VI, L.P.
Its:      General Partner
By:       GTCR Golder Rauner, L.L.C.
Its:      General Partner

By:       /s/ Philip Canfield
     ----------------------------------------
Name:
     ----------------------------------------
Its:      Principal

                       SIGNATURE PAGE TO FIRST AMENDMENT
                        TO STOCK RESTRICTION AGREEMENT<PAGE>

                                                                     Exhibit 4.1

SERIES A COMMON STOCK                                      SERIES A COMMON STOCK

Number                                                                    Shares
                                    [LOGO]

                                CCBN.COM, INC.

             INCORPORATED UNDER THE LAWS OF THE STATE OF DELAWARE

                                                                 SEE REVERSE FOR
                                                             CERTAIN DEFINITIONS

                                                               CUSIP 12500C 10 3

THIS CERTIFIES THAT
                    ------------------------------------------------------------
is the owner of
               -----------------------------------------------------------------

    FULLY PAID AND NONASSESSABLE SHARES OF THE SERIES A COMMON STOCK,
          PAR VALUE $.001 PER SHARE, OF

CCBN.COM, Inc. transferable upon the books of the Corporation in
person or by attorney upon surrender of this certificate duly endorsed or
assigned. This certificate and the shares represented hereby are subject to the
laws of the State of Delaware and the to provisions of the Certificate of
Incorporation and By-laws of the Corporation, as from time to time amended or
restated. This certificate is not valid unless countersigned and registered by
the Transfer Agent and Registrar.

     IN WITNESS WHEREOF, CCBN.COM, Inc. has caused its facsimile corporate seal
and facsimile signatures of its duly authorized officers to be hereunto affixed.

Dated:                                             COUNTERSIGNED AND REGISTERED:
      -----------------                            EQUISERVE TRUST COMPANY, N.A.
                                                    TRANSFER AGENT AND REGISTRAR

                                                   BY
                                                     ---------------------------
                                                     AUTHORIZED SIGNATURE

/s/ Lawrence P. Begley                      /s/ Jeffrey P. Parker
EXECUTIVE VICE PRESIDENT, CHIEF             CHAIRMAN OF THE BOARD OF DIRECTORS
FINANCIAL OFFICER AND TREASURER             AND CHIEF EXECUTIVE OFFICER

                                  [CORPORATE
                                     SEAL]
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                                CCBN.COM, INC.

 THE CORPORATION IS AUTHORIZED TO ISSUE MORE THAN ONE CLASS OF STOCK. THE
CORPORATION WILL FURNISH TO EACH STOCKHOLDER UPON REQUEST WITHOUT CHARGE THE
POWERS, DESIGNATIONS, PREFERENCES AND RELATIVE, PARTICIPATING, OPTIONAL, OR
OTHER SPECIAL RIGHTS OF EACH CLASS OF STOCK OR SERIES THEREOF, AND THE
QUALIFICATIONS, LIMITATIONS OR RESTRICTIONS OF SUCH PREFERENCES AND/OR RIGHTS.

 The following abbreviations, when used in the inscription on the face of
this certificate, shall be construed as though they were written out in full
according to applicable laws or regulations:
<TABLE>
<CAPTION>
<S>                                          <C>
TEN COM - as tenants in common               UNIF GIFT MIN ACT     - Custodian
TEN ENT - as tenants by the entireties                        ----            ----
JT TEN  - as joint tenants with right of                     (Cust)          (Minor)
          survivorship and not as tenants    under Uniform Gifts to Minors
          in common                          Act
                                                -------------
                                                  (State)
</TABLE>
 Additional abbreviations may also be used though not in the above list.

   For value received,                                   , hereby sell,
                      -----------------------------------
assign, and transfer unto

PLEASE INSERT SOCIAL SECURITY OR OTHER
 IDENTIFYING NUMBER OF ASSIGNEE

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                 (PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS,
                    INCLUDING ZIP CODE, OF ASSIGNEE)

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__________________________________________________________________________Shares
of the capital stock represented by the within Certificate, and do hereby
irrevocably constitute and appoint

________________________________________________________________________Attorney
to transfer the said stock on the books of the within named Corporation with
full power of substitution in the premises.

Dated:
     -----------------                  ----------------------------------------

                                  NOTICE: THE SIGNATURE(S) TO THIS ASSIGNMENT
                                  MUST CORRESPOND WITH THE NAME(S) AS WRITTEN
                                  UPON THE FACE OF THE CERTIFICATE IN EVERY
                                  PARTICULAR, WITHOUT ALTERATION OR
                                  ENLARGEMENT OR ANY CHANGE WHATEVER.

SIGNATURE(S) GUARANTEED:
                        --------------------------------------------------------
                        THE SIGNATURE(S) MUST BE GUARANTEED BY AN ELIGIBLE
                        GUARANTOR INSTITUTION (BANKS, STOCKBROKERS, SAVINGS
                        AND LOAN ASSOCIATIONS AND CREDIT UNIONS WITH
                        MEMBERSHIP IN AN APPROVED SIGNATURE GUARANTEE
                        MEDALLION PROGRAM), PURSUANT TO SECURITIES AND EXCHANGE
                        COMMISSION RULE 17Ad-15.

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