Created attachment 108676 [details]
Picture of my screen

Everyday, my system crashes randomly and shows random colors on my screens.
(Yes, dual monitor)
I can't reproduce the bug but it seems to happen on large screen update or
little gnome3 transitions.

complete dmesg: http://pastebin.com/szzwGKx2
uname -r: 3.17.1-1-ARCH

The Xorg.log is untouched since the beginning of this month, so I don't think
it can be relevant for the bugfix.