Bug#644601: [xserver-xorg-core] hard lock-up: [mi] EQ overflowing

[JS]

I had a similar problem with the nvidia driver which resulted in
easy-to-reproduce X server lockups. The Xorg.0.log show the "EQ overflowing"
message followed by message that the xserver was in an infinite loop.

The bug is 642497:
    http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=642497

It was fixed by purging the xserver-xorg-video-nouveau  followed by reinstall
of the nvidia drivers and xserver.

If one tries to install the nvidia driver directly from the NVIDIA blog,
there is a warning that the presence of shared libs from nouveau may cause
problems. After doing this reinstall I've tested extensively and had no problems.

--JS