Bug#675345: gnome-session: Display randomly freezes completely

[Gagou]

I have exactly the same issue with gnome-shell on my computer and on my
laptop. The screen freeze and the mouse can move and the keyboard appear
to be responsive (can switch to tty1). But the screen is not refreshed.
If I was watching a movie, I can hear the sound during freeze.

On tty1, "top" say that gnome-shell take 70% of CPU and Xorg 30%.

The temporary solution: "killall -9 <pid of gnome-shell>" and go back to
tty7.

I think it's the same issue as
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=673824

Nothing special in dmesg or in any other log file. I guess it is because
gnome-session doesn't crash but just run high cpu load and freeze.

I will test every solution you will give me.

Thank you and sorry for my bad english.