We use WI with CAC (smartcard) authentication. I upgraded the WI server from 4 to 4.5 and most people work fine but a few get prompted for their username and password instead of their CAC PIN. They sit on another PC and it works fine. The clients are all 10.x, we've tried reloading the ica client and giving the user a fresh profile on their workstation but it doesn't help. Reimaging the PC fixes it but that's a bit drastic not too mention time consuming. Anyone have any ideas to try?