Strange GDM Problem

[Bill Hartwell]

I just switched my video driver from "ati" to "fglrx" (I have a Radeon 
9200) and everything works just fine, with one minor little (REALLY 
ANNOYING) glitch:

Whenever I log out or reboot, the default GDM greeter crashes. It 
doesn't matter whether it's the themed or plain greeter. Whichever one I 
have set to load by default crashes, and then the other greeter loads 
after I clear away the crash notification window.

Any idea what I should look at to fix this?