802.1x, PEAP, Access denied, unexpected packet

hello,

I have a Windows 2000 SP4 IAS member server in my Server 2003 domain
(native). As far as I can tell, my IAS server is set up correctly, the
server is authorised in AD, my wireless policy is set up (i have read
numerous technet articles on doing this), my radius clients are all set
up, my server certificate is in place, but I cannot connect to my
wireless network. Details of the error from the log is:

Access request for user DOMAIN\useraccount was discarded.
Fully-Qualified-User-Name = <undetermined>
NAS-IP-Address = 192.168.1.125
NAS-Identifier = 001150b4bcc0
Called-Station-Identifier = 001150b4bcc0
Calling-Station-Identifier = 0011504aa4e0
Client-Friendly-Name = accesspoint
Client-IP-Address = 192.168.1.125
NAS-Port-Type = 19
NAS-Port = 14
Reason-Code = 97
Reason = The authentication request was dropped because it contained
an unexpected packet.

The frustrating thing is that I have had this working before on another
2k server, but had to decomission the box and move the service.

Does anyone else use IAS in this configuration?

Gian