I am using Cisco AP1121G access points with Cisco PI21AG cards(and ACU) running WPA2 with LEAP authentication against an ACS server. The problem is that the clients experience a constant slowdown. When a client is started, it will run fine for a couple of hours, but then slows down to the point where it needs to be rebooted. This was not a problem running 128bit WEP encryption. Also, it seems like it is not a problem using our Dell laptops with Dell wireless cards and the Dell wireless utility.