Acer TM 8104 turns off when playing games!

I purchased an Acer Travelmate 8100 in March 2005. Over the past week or so, my notebook has started turning off when I play a game (after about 5-15 minutes). This first started when I was playing a Wolfenstein Enemy Territory mod called True Combat Elite. It has also since happened with Defcon demo and Battlefield 2142 demo.

I have never had this issue prior to installing and playing any of these 3 games.

It has happened about 10 times now. Once or twice I got a solid blue screen for a split second before it turned off. One of the times, Windows noted that it had recovered from a serious error and blamed the video card for the crash but was unable to offer any further help.

I thought it might be heat, but it does not feel any hotter than normal, and Defcon is a not exactly a demanding game. From what I can tell, there are no heat sensors except for the hard drive. I can't think of anything I could do to try and make it run hot outside of a game.

So far I have scanned for viruses/spyware, and ran memtest+, and reinstalled the video drivers (Acer default). Is there anything else I can do to diagnose the problem? I'd like to explore every option before reformatting the system (2nd last resort) and sending it back to Acer (last resort).

Actually, I'd rather throw my system in the garbage before sending it back to Acer, since I am 0/3 with them (unrelated issue). Can I open the system at all without voiding my warranty (which doesn't expire until April 2008), even if it is useless?

Just an update. It turns out that "Automatically Restart" was enabled in Windows Startup and Recovery. This was causing the system to shutdown, but for whatever reason, not restart. With this setting disabled, I just get a solid blue screen with no information whatsoever.

I'm leaning more torwards a driver issue and away from a possible hardware issue, but I'm still not sure what I can do.

Thanks for the tip. Unforunately, I couldn't read the temperature on the CPU at all. I did blow some compressed air into the system as well just in case.

I tried uninstalling the drivers and installing the Omega drivers, but this lead to black textures in-game. I removed those and installed the latest Catalyst using modtool and it seems to be a little better.

I still get ocassional temporary freezes in BF2142, but this is where the other drivers would have crashed completely. I'm wondering if something tampered with my original drivers and triggered this whole mess. At least I was able to play longer than 10 minutes.

It's days like this that remind me why I am primarily a console gamer.