Skimmed through the other responses after reading your logs, so forgive me for repeating, just got back from AZ (miss it already). Your GPU is crashing and your graphics card is causing a kernel panic, this is actually a fairly common thing for GPUs to do (M$ reports that gpu drivers cause approximately 67% of all blue-screens which is a windows kernel-panic).
It's an MSI card, and I use an ATI 7970 myself with minimal problems, but you really need to stick with the 13.12 driver series on linux for most ATI cards right now. Really, anything ATI put out while they were developing mantle for Linux was complete crap so focus on the driver release from December 2012 for now, and wait patiently for the new Omega drivers to be put up to snuff in the next four or five months.
If it's an Nvidia card, just reinstall the proprietary drivers, but I'd go with the binary proprietary drivers from your repo first, and if that's what you've been using then try downloading the driver from nvidia and trying that. If that fails, the open source nouveau driver is really pretty good for day-to-day use and can sometimes handle heavy 3D applications.