Comment # 9 on bug 83792 from Tim Nelson

OK, I've narrowed it down quite a bit.  

The kernel which Fedora (18) calls kernel-debug-3.6.10-4.fc18.x86_64 works. 
Xorg segfaults, but the radeon module successfully loads.  The kernel which
Fedora (19) calls kernel-debug-3.9.5-301.fc19.x86_64 crashes the machine.  

Anyway, I will do some more narrowing down, and I'll try ssh access as well.