Computer can't authenticate with certificate

Computer can't authenticate with certificate but user can authenticate with
certificate odd error on WIN2k3 IAS server i have included a copy from the
error log

Event Type: Error
Event Source: IAS
Event Category: None
Event ID: 16
Date: 1/09/2006
Time: 7:25:40 PM
User: N/A
Computer: SVR-01
Description:
A RADIUS message with the Code field set to 2, which is not valid, was
received on port 1812 from RADIUS client Dlink1. Valid values of the RADIUS
Code field are documented in RFC 2865.

For more information, see Help and Support Center at
http://go.microsoft.com/fwlink/events.asp.

the Computer has a valid certificate

does any one have any suggestions

the AP is a Dlink DWL-7100AP