In 3.0 release and higher, the phone has an auto EAP mode, where it will give predecence to EAP-FAST over LEAP. Will try LEAP after EAP-FAST failure. Can also force the EAP mode in the network profile setup.
If using EAP-FAST w/ the 4400 controller, will need to increase the 802.1x timeout on the controller to at least 20 seconds vs default of 2. Do "config advanced eap request-timeout 20" via console.
Will also need to ensure that the radius server also has automatic PAC provisioning enabled if using EAP-FAST as manual provisioning is not supported.