https://bugs.freedesktop.org/show_bug.cgi?id=57567
--- Comment #45 from Alexandre Demers alexandre.f.demers@gmail.com --- (In reply to comment #44)
Does disabling acceleration help?
Option "NoAccel" "True"
In the device section of you xorg.conf
I was able to log in, launch "xset dpms force off". My screen turned off. After waking it up, the display was still shifted.