I have the same problem, down to the identical stack trace in the logs. It mostly happens when I use external monitor instead of my laptop's screen. Package versions are the same as with the original reporter's:
ii xserver-common 2:1.7.4-1
common files used by various X servers
ii xserver-xorg 1:7.5+1
the X.Org X server
ii xserver-xorg-core 2:1.7.4-1
Xorg X server - core server
ii xserver-xorg-input-evdev 1:2.3.2-3
X.Org X server -- evdev input driver
ii xserver-xorg-input-kbd 1:1.4.0-1
X.Org X server -- keyboard input driver
ii xserver-xorg-input-mouse 1:1.5.0-1
X.Org X server -- mouse input driver
ii xserver-xorg-video-intel 2:2.9.1-2
X.Org X server -- Intel i8xx, i9xx display
driver
xrandr and lspci outputs attached.
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Dmitry Borodaenko
xrandr.log
Description: Binary data
lspci.log
Description: Binary data
