I can open as many instances of IE7 as I want and I get prompted for a cert each time (but no PIN). However, if I close any of the instances of IE7, then on the next open I get the PIN prompt. So it seems to me that the IE7 program is doing something when it is closed to tell the smart card to "expire" the current PIN. I would like to find out what IE7 is doing to cause that to happen (when it closes) because I want my program to be able to do that too. Any ideas on how I could find that out?
Thanks!
Resetting the card will exipre the PIN. See this answer for more information.