Comment 4 for bug 38484

I notice you mention fglrx briefly in your initial post. Can you try "dpkg --purge xorg-driver-fglrx" and THEN "dpkg-reconfigure xserver-xorg" and pick "ati"?

Then reboot completely to clear any scary DRM madness that the kernel may have loaded.

(you might even try a cold power off and on, to make sure the video card doesn't have some messed up registers that just deperately need a reset)