I have a WPA TKIP wireless network, so clients don't need a key to connect. It is using Group Policy also.
The other day I had a client that couldn't connect. It kept saying it couldn't authenticate. I tried rebooting, updating group policy, disabling/enabling wireless adapter etc but nothing worked.
The next day it fixed itself. Anyone got any ideas about what could have caused this? Would have been good to fix it at the time!