https://bugs.freedesktop.org/show_bug.cgi?id=36542
--- Comment #7 from Matt Novenstern fisxoj@gmail.com 2011-06-25 10:55:51 PDT --- Now that I can boot at all with my 6850, I'm getting this bug, too. Seems to be triggered by 3d, I don't think gnome shell has triggered it alone yet.
Same dmesg.