We have to log in using access cards. Some of my users receive an lsass.exe error with an R6025 pure virtual function call when logging on. Once they receive this error they can not logon to that particular workstation until someone else logs in/logs out. Then the user who orginally had the problem can now login to the workstation. We are running Vista X32 on Dell Optiplex 745. This problem does not happen with each logon attempt. Thanks, Walt