Is your address, or the CC registered overseas? That could be part of it. Best bet is probably to print out an old statement or call the CC company and have them fax/email you one.

Is it your skymiles account that you booked the award with, and is the CC in your name? If so, it will probably be okay at the airport. If the miles and/or CC were from someone else but you are traveling, then you might have a problem.