Document:

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                                  Exhibit 4.25

                                 April 26, 2002

Speedcom Wireless Corporation
1748 Independence Boulevard, D-4
Sarasota, Florida 34243
Attention: Sara Byrne

DMG Legacy Fund LLC
DMG Legacy Institutional Fund LLC
DMG Legacy International Ltd.
c/o DMG Advisors LLC
One Sound Shore Drive, Suite 202
Greenwich, CT 06830

                  Re:  Letter Agreement
                       ----------------

Ladies and Gentlemen:

         This Letter Agreement is the Letter Agreement referred to in the Letter
Loan Agreement (the "Letter Loan Agreement") dated as of April 26, 2002 by and
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among Speedcom Wireless Corporation (the "Company"), DMG Legacy Fund LLC, DMG
                                          -------
Legacy Institutional Fund LLC and DMG Legacy International Ltd. (collectively,
the "Lenders"). Capitalized terms used and not otherwise defined herein shall
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have the meanings set forth for such terms in the Letter Loan Agreement.

         Pursuant to Sections 2(c) and 4(a)(i) of the Letter Loan Agreement and
as an inducement to the Lenders to make the Loans, I hereby agree not to sell or
transfer any of the shares of common stock of the Company as set forth on
Schedule I to this Letter Agreement beneficially owned by me, including,
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without, limitation, any shares under my control (the "Shares"). I hereby
                                                       ------
acknowledge and agree that so long as the Loans are outstanding, I will not sell
or transfer any of the Shares.

                                                     Sincerely,

                                                     Michael McKinney

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                                   Schedule I
                                   ----------

Shares directly owned by Michael McKinney: 1,849,995

Shares owned by Michael McKinney as custodian for Molly Michel McKinney: 321,780

Shares owned by Michael McKinney as custodian for Ryan Lewis McKinney: 321,780

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                                  Exhibit 4.26
                                  ------------

                            AGREEMENT TO VOTE SHARES
                            ------------------------

         THIS AGREEMENT TO VOTE SHARES ("Agreement") is executed as of April 26,
2002, by and between Michael W. McKinney ("McKinney") and Speedcom Wireless
Corporation ("Speedcom").

         WHEREAS, certain lenders of funds to Speedcom (the "Lenders") have
required that McKinney enter into this Agreement as a condition of lending
funds;

         NOW, THEREFORE, in consideration of the premises, the parties hereto
agree as follows:

     1.   Agreement To Vote Shares. McKinney agrees to vote, or cause to be
          ------------------------
voted, all of the shares of common stock of Speedcom ("Common Stock") over which
he has voting authority, at any meeting of the stockholders of Speedcom and in
any action by written consent of the stockholders of Speedcom, in favor of a
bona fide merger, stock sale or sale of all or substantially all of Speedcom's
assets (a "Change of Control Transaction") with an acquiror acceptable to the
Lenders which would result in a change in control of Speedcom and which has been
approved by Speedcom's Board of Directors. In addition, McKinney shall use his
best efforts to cause his former spouse to vote shares of Common Stock over
which she has voting authority in the same manner.

     2.   Miscellaneous.
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          (a)  This Agreement shall be governed by, and construed and enforced
     in accordance with, the laws of the State of Delaware without regard to its
     conflicts of laws provisions.

          (b)  This Agreement may not be assigned by any party hereto without
     the prior written consent of the other parties hereto.

          (c)  This Agreement supersedes any prior agreement or understanding,
     whether written or oral, between the parties with respect to the subject
     matter of this Agreement. This Agreement shall be binding upon and shall
     inure to the benefit of the parties and their respective heirs, executors,
     legal representatives, successors and permitted assigns. This Agreement may
     be amended, modified, superseded, cancelled, renewed or extended, and the
     terms and conditions hereof may be waived, only by a written instrument
     signed by the parties or, in the case of a waiver, by the party waiving
     compliance.

          (d)  This Agreement may be executed in separate counterparts, any one
     of which need not contain the signatures of more than one party, but all
     such counterparts taken together shall constitute one and the same
     agreement.

          (e)  This Agreement shall terminate upon the earlier of (1) the
     payment of all obligations due to the Lenders and (2) the closing of a
     Change of Control Transaction.

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         IN WITNESS WHEREOF, the undersigned have executed this Agreement as of
the date first written above.

_________________________
Michael W. McKinney

SPEEDCOM WIRELESS CORPORATION

By:_________________________

Its:__________________________

                                      -2-<PAGE>

                                                                  Exhibit 10.179

                              CONSENT AND AMENDMENT

      THIS CONSENT AND AMENDMENT (this "Consent"), dated as of February 4, 2002,
                                        -------
to the Loan Agreement referenced below, is by and among Pharmaceutical Product
Development, Inc., a North Carolina corporation (the "Borrower"), the
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Subsidiaries of the Borrower identified on the signature pages hereto (the
"Guarantors") and Wachovia Bank (the "Bank").
 ----------                           ----

                               W I T N E S S E T H

      WHEREAS, a $50 million credit facility has been established in favor of
the Borrower pursuant to the terms of that Amended and Restated Loan Agreement
dated as of July 31, 2001 (as amended, modified, supplemented and extended from
time to time, the "Loan Agreement") among the Borrower, the Guarantors and the
                   --------------
Bank;

      WHEREAS, the Borrower intends to acquire, either directly or indirectly
through one or more of its Subsidiaries, by way of merger, purchase or
otherwise, all of the capital stock of Medical Research Laboratories
International, Inc. and Medial Research Laboratories International B.V.B.A.
(collectively, the "Proposed Acquisition");
                    --------------------

      WHEREAS, the Borrower has requested that the Bank consent to the Proposed
Acquisition; and

      WHEREAS, the Bank has agreed to consent to the Proposed Acquisition on the
terms and conditions set forth herein.

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

      1.  Defined Terms. Terms used herein not otherwise defined herein shall
          -------------
have the meanings provided to such terms in the Loan Agreement.

      2.  Consent to Proposed Acquisition. Notwithstanding the provisions of
          -------------------------------
Section 6.7 and Section 6.8 of the Loan Agreement, the Bank hereby consents to
the Proposed Acquisition provided that the Proposed Acquisition is consummated
substantially in accordance with the terms set forth on Schedule 1 hereto (or,
to the extent of any material deviations, such deviations shall have been
disclosed to the Bank). The Bank agrees that the Proposed Acquisition shall not
be deemed an "Investment" for purposes of Section 6.8.

      3.  Amendment. Section 6.8 of the Loan Agreement is amended by adding the
          ---------
following sentence after subsection (i):

          "For purposes of this Section 6.8, the term "Investment"
          shall not include any merger, consolidation or acquisition
          of all or substantially all of the capital stock (or other
          equity interest) or assets of any other Person which is
          subject to Section 6.7 of the Loan Agreement."

      4.  Conversion of PPD Development, LLC. Effective December 31, 2001, PPD
          ----------------------------------
Development, LLC, a Texas limited liability company, was converted into a Texas
limited partnership, and its name following such conversion is PPD Development,
LP. The Bank hereby consents to such conversion and agrees that any provision of
the Loan Agreement relating to PPD Development, LP's form of organization is
amended accordingly.

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     5.   Conditions Precedent. This Consent shall be effective as of the date
          --------------------
hereof upon execution hereof by the Borrower, the Guarantor and the Bank.

     6.   Reaffirmation of Representations and Warranties. The Borrower hereby
          -----------------------------------------------
affirms that the representations and warranties set forth in the Loan Agreement
are true and correct as of the date hereof.

     7.   Reaffirmation of Guaranty. The Guarantor (i) acknowledges and consents
          -------------------------
to all of the terms and conditions of this Consent, (ii) affirms all of its
obligations under the Loan Agreement and (iii) agrees that this Consent and all
documents executed in connection herewith do not operate to reduce or discharge
the Guarantor's obligations under the Loan Agreement.

     8.   No Other Changes. Except as modified hereby, all of the terms and
          ----------------
provisions of the Loan Agreement and the other Loan Documents (including
schedules and exhibits thereto) shall remain in full force and effect.

     9.   Counterparts. This Consent may be executed in any number of
          ------------
counterparts, each of which when so executed and delivered shall be deemed an
original and it shall not be necessary in making proof of this Consent to
produce or account for more than one such counterpart.

     10.  Governing Law. This Consent shall be deemed to be a contract made
          -------------
under, and for all purposes shall be construed in accordance with, the laws of
the State of North Carolina.

                            [Signature Pages Follow]

                                       2

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      IN WITNESS WHEREOF, each of the parties hereto has caused a counterpart
of this Consent to be duly executed and delivered as of the date first above
written.

BORROWER:                   PHARMACEUTICAL PRODUCT DEVELOPMENT, INC.,
                            a North Carolina corporation

                            By:  /s/ Fred B. Davenport, Jr.
                               ------------------------------------------
                            Name:  Fred B. Davenport, Jr.
                            Title: President

GUARANTORS:                 PPD DEVELOPMENT, LP,
                            a Texas limited partnership

                            By:  /s/ Fred B. Davenport, Jr.
                               ------------------------------------------
                            Name:   Fred B. Davenport, Jr.
                            Title:  President

BANK:                       WACHOVIA BANK

                            By:  /s/ Douglas T. Davis
                               ------------------------------------------
                            Name:   Douglas T. Davis
                            Title:  Director

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