Cherry Swipe error on a certain computer

I am getting an Authorization error when swiping cc's on a single computer using a new Cherry keyboard.  The keyboard works on other computers just fine.  The error I'm getting when authorizing is "AMOUNT ENTRY ERR 305".  This error suggests non-numeric entry in the amount field.  That has me baffled.    

I've done some basic swipe tests with the keyboard on working & non-working machines and they look identical. There must be some non-display characters coming from the swipe gumming up the works.

Anybody seen anything like this before?  The machine having the problem is XP and the working machine is Win7.  Possible driver issue?