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Exhibit 10.21

AMENDMENT NO. 1 TO LOAN AGREEMENT

THIS AMENDMENT NO. 1 (Amendment) is made and entered into as of February
19, 2003, by and between ZAMBA CORPORATIONand ENTRX CORPORATIONand modifies
the Loan Agreement (Loan) dated November 4, 2002, between the parties.
Except as expressly set forth herein, the terms and conditions of the Loan
shall continue in full force and effect. All references to section numbers
below refer to the respective section numbers in the Loan. Capitalized terms
shall bear the meanings for such terms set forth in the Loan.



| | 1. |  | Section 3.1.4 is modified by adding the following to the end of the
Section: Subject to Borrowers receipt from Lender of $450,000 on or
prior to February 19, 2003, and $200,000 on or prior to March 15, 2003,
representing the entire remaining balance of the Second Advance, Lender
shall be entitled to convert the aggregate principal amount of the First
Advance and the Second Advance that have been provided to Borrower, as
well as $6,888.89 of interest that has accrued prior to this Amendment,
into shares of NextNet Wireless, Inc. (NextNet) Series A Preferred
Stock held by Borrower (the Shares) at a per share conversion price
that is the lesser of $6.00 per share or such lower initial per share
price (on a common share equivalent basis, without giving effect to
differences in rights or to anti-dilution provisions or any other
purchase price adjustments set forth in the NextNet financing agreement)
that NextNet agrees to receive for any sale of other preferred stock in
an amount that is at least one million dollars ($1,000,000.00) before
June 30, 2003. A prior election by Lender to convert the Advances it
provided and eligible interest under this Agreement shall not affect
its eligibility to receive the benefit of conversion at a lower initial
per share price from a subsequent NextNet financing agreement if Lender
would have otherwise been eligible pursuant to this Agreement to obtain
such lower initial per share price if it had waited until the NextNet
financing agreement was completed to exercise its conversion rights. If
Borrower does not receive the entire remaining balance of the Second
Advance by remittances from Lender to Borrower of the amounts of
$450,000 on or prior to February 19, 2003, and $200,000 on or prior to
March 15, 2003, the remedies set forth above that have not already been
effectuated pursuant to provisions of this Amendment shall apply.
Notwithstanding the above, each party acknowledges that Lenders receipt
of the Shares, at any price, may be subject to the rights of first
refusal on the parts of NextNet and certain of its investors as set
forth in the Right of First Refusal Agreement.
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| | 2. |  | Section 3.1.5 is modified by inserting, at the end of the paragraph,
the following: No interest shall accrue or become due during any period
in which there exists an Event of Default by Lender. Any interest not
paid prior to the date of this Amendment shall not be due if during such
period there was an Event of Default by Lender.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
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| | 3. |  | Section 3.1.3 is eliminated in its entirety and Borrower hereby
expressly waives the obligation of Lender to advance the Third Advance,
and Section 6.2 is eliminated in its entirety and Lender expressly
waives its rights to convert all outstanding Advances under the Note
into shares of Borrowers common stock.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
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| | 4. |  | Section 3.3 of the Loan is deleted and the parties acknowledge that
all of Borrowers rights and Lenders obligations related to the Option
set forth in the Loan are terminated upon execution of this Amendment,
including but not limited to any obligation of Borrower to reserve a
sufficient amount of Shares for exercise of the Option.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
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| | 5. |  | Section 4.12 is modified by deleting 1,083,333 from the sixth line
and replacing same with 583,333.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
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| | 6. |  | Section 6.1.1 is modified by adding, prior to The NextNet Conversion
Rate in the eighth line, the following: Subject to Borrowers receipt
from Lender of $450,000 on or prior to February 19, 2003, and $200,000
on or prior to March 15, 2003, representing the entire remaining balance
of the Second Advance, . . .                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
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| | 7. |  | Section 6.3.1 is modified by deleting the third paragraph and
replacing it with the following: Upon execution of this Amendment, the
parties shall instruct the Collateral Agent to return 250,000 shares of
Series A Preferred Stock of NextNet from the Collateral to Borrower. On
July 1, 2003, the Collateral Agent shall return to Borrower all shares of
Collateral not previously issued or returned.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        

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



| | ZAMBA CORPORATION,
a Delaware corporation
By /s/ Michael H. Carrel
Name: Michael H. Carrel
Title: Chief Financial OfficerENTRX CORPORATION,
a Delaware corporation
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| | By /s/ Brian Niebur
Name: Brian Niebur
Title: Chief Financial Officer
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