WPA2 TKIP has been cracked .. but only with a dictionary. There is also the proof of concept Michael attack but you need to have QOS enabled.
WPA2 AES has NOT been cracked yet .. it can still be DOS'd tho.
What someone could be doing is deauthing your clients, however if i was the attacker a far more effective attack would be to look at the probe requests from each client and run a rogue AP. If you can gain access to just one of the users PC's your basically inside the network as you can obviously recover the wireless keys and any other keys you use for authentication.



once said ... if its a high security environment don't even think about running wireless!
