If a computer that is running Windows Vista or Windows Server 2008 uses a wireless network connection, you cannot use the EAP method to authenticate the computer
Consider the following scenario. You try to use the Extensible Authentication Protocol (EAP) method to authenticate a client computer that is running Windows Vista or Windows Server 2008 by using a wireless network connection. In this scenario, the EAP authentication fails.
For more information on this issue, including potential causes, workarounds, and resolutions, see: Microsoft KB Article KB967802.