We also have similar problem. We have a 2006 Series Wireles LAN Controller (AIR-WLC2006-K9) set up with 5 deployed Aironet 1130AG Series (AIR-LAP1131AG-A-K9) access points. We have one wireless network configured using WPA + WPA2, AES encryption, 802.1X key management, RADIUS with local EAP Authentication. All APs are connected via a private switch (not VLANed) and powered using PoE. We have been having a consistent problem with the wireless network
dropping clients to the point where the majority of our employees are turning off their wireless cards and plugging in via ethernet due to the instability of the network. People connecting using 802.11A seem to have a more stable connection to the APs, but still have problems with getting dropped. The logging gives us little to work with other than AAA
Authentication messages. We have seen a number of "Max AAA authentication attempts
exceeded messages" in the logs. We have been banging our heads against this for some time now and have never been able to find a configuration solution that garauntees a decent quality of service to our wireless clients. THe controller crash and AP crash logs are empty. And we are getting similar error.