Freeradius 2.x + MySQL: Failed to authenticate the user

Hello all, I have a new setup with Freeradius 2.1.7, Dialup Admin 1.80 and MySQL 5.0.77 running under Red Hat ES 5.4. Access from Freeradius to MySQL is working fine but user 'dummy' does not get authenticated. After hours of searching through my setup it seems to me that the problem is rather related to my Freeradius configuration than to MySQL. I tested locally with radtest and remotly with NTRadPing: Access-Reject. From the attached debug output can you see why? Thanks in advance! Cheers, Alexander