Or maybe the machine was broken?
I have been idine for 9 years - before I think even airlines participated (I think - it was just cash back then and it was not tied to your CC, you had to present your idine card) and I seriously doubt that servers notice Idine or probably even look very closely at the credit card to see that it is an affinity card (why do they care if you are Citibank AAdvantage?).