<PAGE>
                                                                 EXHIBIT 10.14.5

                                                                  Execution Copy

                       FIFTH AMENDMENT TO CREDIT AGREEMENT

         This FIFTH AMENDMENT TO CREDIT AGREEMENT (this "Amendment"), made and
entered into as of December 17, 2002, is by and between RTW, Inc., a Minnesota
corporation (the "Borrower"), and U.S. Bank National Association, a national
banking association (the "Bank").

                                    RECITALS

         1. The Bank and the Borrower entered into a Credit Agreement dated as
of March 31, 2000 as amended by a First Amendment dated as of May 4, 2000, a
Second Amendment dated as of March 28, 2001, a Third Amendment dated as of
September 29, 2001 and a Fourth Amendment and Limited Waiver of Default dated as
of March 22, 2002 (as amended, the "Credit Agreement"); and

         2. The Borrower desires to amend certain provisions of the Credit
Agreement, and the Bank has agreed to make such amendments, subject to the terms
and conditions set forth in this Amendment.

                                    AGREEMENT

         NOW, THEREFORE, for good and valuable consideration, the receipt and
adequacy of which are hereby acknowledged, the parties hereto hereby covenant
and agree to be bound as follows:

         Section 1. Capitalized Terms. Capitalized terms used herein and not
otherwise defined herein shall have the meanings assigned to them in the Credit
Agreement, unless the context shall otherwise require.

         Section 2. Amendment. Section 6.19 of the Credit Agreement is hereby
amended in its entirety to read as follows:

                     Section 6.19 [Intentionally Omitted].

         Section 3. Effectiveness of Amendments. The amendments contained in
this Amendment shall become effective upon delivery by the Borrower of, and
compliance by the Borrower with, the following:

         3.1 This Amendment, duly executed by the Borrower.

         3.2 A copy of the resolutions of the Board of Directors of the Borrower
authorizing the execution, delivery and performance of this Amendment certified
as true and accurate by its Secretary or Assistant Secretary, along with a
certification by such Secretary or Assistant Secretary (i) certifying that there
has been no amendment to the Articles of Incorporation or Bylaws of the Borrower
since true and accurate copies of the same were delivered to the Bank with a
certificate of the Secretary of the Borrower dated
<PAGE>

March 31, 2000, except for an amendment to the Articles of Incorporation dated
November 7, 2002 allowing for a reverse split of the Borrower's common stock, a
true and correct certified copy of which has been delivered by the Secretary of
the Borrower, and (ii) identifying each officer of the Borrower authorized to
execute this Amendment, and certifying as to specimens of such officer's
signature and such officer's incumbency in such offices as such officer holds.

         3.3 The Borrower shall have satisfied such other conditions as
specified by the Bank, including payment of all unpaid legal fees and expenses
incurred by the Bank through the date of this Amendment in connection with the
Credit Agreement.

Section 4. Representations, Warranties, Authority, No Adverse Claim.

         4.1 Reassertion of Representations and Warranties, No Default. The
Borrower hereby represents that on and as of the date hereof and after giving
effect to this Amendment (a) all of the representations and warranties contained
in the Credit Agreement are true, correct and complete in all respects as of the
date hereof as though made on and as of such date, except for (i) Section 4.20,
and (ii) changes permitted by the terms of the Credit Agreement, and (b) there
will exist no Default or Event of Default under the Credit Agreement as amended
by this Amendment on such date which has not been waived by the Bank.

         4.2 Authority, No Conflict, No Consent Required. The Borrower
represents and warrants that the Borrower has the power and legal right and
authority to enter into the Amendment Documents and has duly authorized as
appropriate the execution and delivery of the Amendment Documents and other
agreements and documents executed and delivered by the Borrower in connection
herewith or therewith by proper corporate action, and none of the Amendment
Documents nor the agreements contained herein or therein contravenes or
constitutes a default under any agreement, instrument or indenture to which the
Borrower is a party or a signatory or a provision of the Borrower's Articles of
Incorporation, Bylaws or any other agreement or requirement of law, or result in
the imposition of any Lien on any of its property under any agreement binding on
or applicable to the Borrower or any of its property except, if any, in favor of
the Bank. The Borrower represents and warrants that no consent, approval or
authorization of or registration or declaration with any Person, including but
not limited to any governmental authority, is required in connection with the
execution and delivery by the Borrower of the Amendment Documents or other
agreements and documents executed and delivered by the Borrower in connection
therewith or the performance of obligations of the Borrower therein described,
except for those which the Borrower has obtained or provided and as to which the
Borrower has delivered certified copies of documents evidencing each such action
to the Bank.

         4.3 No Adverse Claim. The Borrower warrants, acknowledges and agrees
that no events have been taken place and no circumstances exist at the date
hereof which would give the Borrower a basis to assert a defense, offset or
counterclaim to any claim of the Bank with respect to the Obligations.


                                      -2-
<PAGE>


         Section 5. Affirmation of Credit Agreement, Further References,
Affirmation of Security Interest. The Bank and the Borrower each acknowledge and
affirm that the Credit Agreement, as hereby amended, is hereby ratified and
confirmed in all respects and all terms, conditions and provisions of the Credit
Agreement, except as amended by this Amendment, shall remain unmodified and in
full force and effect. All references in any document or instrument to the
Credit Agreement are hereby amended and shall refer to the Credit Agreement as
amended by this Amendment. The Borrower confirms to the Bank that the
Obligations are and continue to be secured by the security interest granted by
the Borrower in favor of the Bank under the Security Documents, and all of the
terms, conditions, provisions, agreements, requirements, promises, obligations,
duties, covenants and representations of the Borrower under such documents and
any and all other documents and agreements entered into with respect to the
obligations under the Credit Agreement are incorporated herein by reference and
are hereby ratified and affirmed in all respects by the Borrower.

         Section 6. Merger and Integration, Superseding Effect. This Amendment,
from and after the date hereof, embodies the entire agreement and understanding
between the parties hereto and supersedes and has merged into this Amendment all
prior oral and written agreements on the same subjects by and between the
parties hereto with the effect that this Amendment, shall control with respect
to the specific subjects hereof and thereof.

         Section 7. Severability. Whenever possible, each provision of this
Amendment and the other Amendment Documents and any other statement, instrument
or transaction contemplated hereby or thereby or relating hereto or thereto
shall be interpreted in such manner as to be effective, valid and enforceable
under the applicable law of any jurisdiction, but, if any provision of this
Amendment, the other Amendment Documents or any other statement, instrument or
transaction contemplated hereby or thereby or relating hereto or thereto shall
be held to be prohibited, invalid or unenforceable under the applicable law,
such provision shall be ineffective in such jurisdiction only to the extent of
such prohibition, invalidity or unenforceability, without invalidating or
rendering unenforceable the remainder of such provision or the remaining
provisions of this Amendment, the other Amendment Documents or any other
statement, instrument or transaction contemplated hereby or thereby or relating
hereto or thereto in such jurisdiction, or affecting the effectiveness, validity
or enforceability of such provision in any other jurisdiction.

         Section 8. Successors. The Amendment Documents shall be binding upon
the Borrower and the Bank and their respective successors and assigns, and shall
inure to the benefit of the Borrower and the Bank and the successors and assigns
of the Bank.

         Section 9. Legal Expenses. As provided in Section 8.2 of the Credit
Agreement, the Borrower agrees to reimburse the Bank, upon execution of this
Amendment, for all reasonable out-of-pocket expenses (including attorney' fees
and legal expenses of Dorsey & Whitney LLP, counsel for the Bank) incurred in
connection with the Credit Agreement, including in connection with the
negotiation, preparation and execution of the Amendment Documents and all other
documents negotiated, prepared and executed in connection with the Amendment
Documents, and in enforcing the obligations of the Borrower under the Amendment
Documents, and to pay and save the Bank harmless from all liability for, any
stamp or other taxes which may be payable


                                      -3-
<PAGE>

with respect to the execution or delivery of the Amendment Documents, which
obligations of the Borrower shall survive any termination of the Credit
Agreement.

         Section 10. Headings. The headings of various sections of this
Amendment have been inserted for reference only and shall not be deemed to be a
part of this Amendment.

         Section 11. Counterparts. The Amendment Documents may be executed in
several counterparts as deemed necessary or convenient, each of which, when so
executed, shall be deemed an original, provided that all such counterparts shall
be regarded as one and the same document, and either party to the Amendment
Documents may execute any such agreement by executing a counterpart of such
agreement.

         Section 12. Governing Law. THE AMENDMENT DOCUMENTS SHALL BE GOVERNED BY
THE INTERNAL LAWS OF THE STATE OF MINNESOTA, WITHOUT GIVING EFFECT TO CONFLICT
OF LAW PRINCIPLES THEREOF, BUT GIVING EFFECT TO FEDERAL LAWS APPLICABLE TO
NATIONAL BANKS, THEIR HOLDING COMPANIES AND THEIR AFFILIATES.

            [The remainder of this page is intentionally left blank.]



                                      -4-
<PAGE>


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

BORROWER:                        RTW, INC.



                                 By:     /s/ Jeffrey B. Murphy
                                     ------------------------------

                                 Title: Chief Financial Officer
                                        ---------------------------


BANK:                            U.S. BANK NATIONAL ASSOCIATION



                                 By:    /s/ Christine J. Geer
                                     ------------------------------

                                 Title: Corporate Banking Officer
                                        ---------------------------


             (Signature Page to Third Amendment to Credit Agreement)
                                      S - 1