I'm still suffering from this problem with -27. X freezes for me once every 2-3 days. The symptons are as you describe. It seems to be a regression from 11.10.
3.2.0-27-generic #43-Ubuntu SMP Fri Jul 6 14:25:57 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux
At the time of the freeze /sys/kernel/debug/dri/0/i915_error_state says "no error state collected"
I've installed mainline 3.4 to see if the problem goes away.
I'm still suffering from this problem with -27. X freezes for me once every 2-3 days. The symptons are as you describe. It seems to be a regression from 11.10.
3.2.0-27-generic #43-Ubuntu SMP Fri Jul 6 14:25:57 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux
At the time of the freeze /sys/kernel/ debug/dri/ 0/i915_ error_state says "no error state collected"
I've installed mainline 3.4 to see if the problem goes away.