Did you check the date on your certifcates? If all of the machines are not connecting at the same time I would look to see if the certificate for the server or the ones for the clients have expired. And make sure that the date/time is right on all machines, Radius Server, and AP/WLC just in case. Then I would look at communication between radius and the AP (or WLC). Check the logs on both sides as RADIUS is a connectionless protocol and so one side might think it's fine when it's not.Last I would look at infrastructure services like DHCP.
BTW...your wired network and wireless are probably pretty different so don't consider what is happening on your wired network much of a indication of the problem on your wireless. I.E. even if your DHCP on the wired is workin that doesn't mean that the AP/WLC is briding it or relaying it correctly.
Also...when you get limited connectivity on XP with the wireless client it could mean a variety of things. XP will often says that the wireless is connected when authentication
actually failed...so limited connectivity could mean (1. Auth Failed or 2. DHCP failed). You can make sure it's not a DHCP problem by giving the wirless card an static IP address.
