Win2k3 Stand-Alone CA and IAS

Greetings,

I am trying to setup 802.1x authenicates using self-signed certificates and
Microsoft IAS to authenticate to AD. Everything seems to be setup correctly,
however for some reason the IAS server comes back and tells me the username
or password is incorrect...even though the username it says is denied access
actually exists in AD and can log in just fine.

The Stand-Alone CA is running win2k3, the IAS server is Win2k3, the AD
domain is win2k native mode.

I am not certain what I am doing wrong here. Please help.

Thank you.