Comment 485 for bug 993187

I was affected by this bug on Samsung E500 laptop, happened a lot, especially when on battery use, solved it after a long googling which returned me two possible solutions:
-ugrading kernel to 3.4
-adding this to kernel boot options: i915.i915_enable_rc6=0

The last solution was the fix, didn't have a single crash of those since then (more than 2 months ago).
As it happened mostly on battery usage, it really does make sense that it is related to the unstability of intel driver for sandy bridge which you can find easily googling for enable rc6 and sandy bridge.

The only thing is, that battery life gets a little less... :S but at least this makes your system plain usable again :)