RADIUS on Leopard 10.5 Server

Is anyone else using the RADIUS service on 10.5 server? I was able to get it working briefly with an AirPort Base Station, but now authentication is failing with the following: Tue Jul 15 10:20:00 2008 : Auth: rlm_opendirectory: User is authorized. Tue Jul 15 10:20:00 2008 : Auth: rlm_opendirectory: User is authorized. Tue Jul 15 10:20:00 2008 : Auth: rlm_opendirectory: User is authorized. Tue Jul 15 10:20:02 2008 : Auth: rlm_opendirectory: User is authorized. Tue Jul 15 10:20:02 2008 : Auth: rlm_opendirectory: User is authorized. Tue Jul 15 10:20:02 2008 : Error: rlm_mschap: authentication failed -14090 So it looks like open directory is successfully seeing the user, but MS CHAP is failing. Anyone seen this before? I have not used RADIUS that much, but it looks like a pretty stock freeRADIUS install. Any help would be appreciated. Thanks, -Iain