We have a bunch of WiFi enabled PDA clients that seem to have an issue with WPA-PSK. They seems to work fine for about 1 - 2 hours, but then they are knocked off the network. Running a wireshark trace it showed that the AP sends 3 WPA-PSK handshakes that the PDA never responds to. The AP then sends a DEauth with reason code 4 - which indicates that the AP or backend controller cancelled the session due to inactivity.
Access point: Cisco AIR-LAP1242AG-A-K9.
Anyone experience this issue? Anything to look for?