I understand that it's probably overheating. This is something that wasn't an issue before I updated to 213 to fix the RAGE issue. Now it runs smoothly but the laptop overheats after like 15 minutes of gaming. I verified in the Power Settings that the cooling is set to active and not passive but the system still overheats all the time.
Well it's not so much that I have any software running as the laptop just shuts itself off. If I have Asus Probe running in the background it will start beeping 5 seconds after I start any game. I've had the laptop for a little over a year now. It has the ATI 5800HD card in it so I've been having quite a few issues. : /
Overheating is a definite possibility, and you have had your system long enough to consider a compressed gas blow out where you open the laptop and blow compressed gas from the inside to the outside through the fan exhausts to remove built up dust, or possibly even a repaste. However, especially as a gamer, it is in your best interest to run a utility such as SpeedFan or HWInfo to montor your CPU and GPU temps. This would confirm overheating as the cause in your case.
My suspicion is the BIOS update is NOT responsible for the overheating, but that you were on the margin of shutdown and just happened to cross over that margin shortly after the flash.
The funny thing is that a previous BIOS update fixed an overheating issue. The laptop was working ok until Rage came out. It was then suggested to me that I update my BIOS to 213 and now the system is shutting itself down again. I have no idea why it would be an issue with dust. I'll check it out tonight though.