I recently upgraded to Windows XP Service Pack 2 (SP2) and am having trouble with wireless networking. I can authenticate at logon, but I can no longer roam between Access Points (APs) or reauthenticate on an AP without logging off, then relogging on. I use Protected Extensible Authentication Protocol (PEAP) and Temporal Key Integrity Protocol (TKIP) for authentication and encryption. Do you know what the problem might be?
I would guess you're using Cisco Systems' Secure Access Control Server (ACS) for Windows 3.2 for your Remote Authentication Dial-In User Service (RADIUS) server. I've seen this same problem occur after upgrading a system to XP SP2, and it doesn't seem to matter which wireless adapter you use on your notebook. This problem occurs when the fast reconnect option is disabled on the client and enabled on the ACS server. To resolve the problem, clear the fast reconnect option on the ACS server, click Submit, then click Restart. Alternatively, you can enable fast reconnect on your client.
—Bob Chronister