Asus G1s Starcraft 2 - after an hour or so of playing shuts down and screen flickers on reboot.

I have a asus g1s thats about 3 years old with windows7. I just cleaned out the dust and took that black tape off the back of the cpu cover hoping to lower the heat in my computer. Well I just started to play starcraft 2 and I can't even play for more than an hour without it shutting off on me. I am guessing its the heat, but when I check speedfan I haven't seen the gpu or cpu go in to the 90s. The bottom of the notebook is super hot, though. Also as soon as it shuts down it tries to boot back up again and fails - then I boot again and it works but then the screen flickers in brightness for a while. I am wondering if this is strictly a heat issue or could be something else. Should I retape the cpu cover vents? And will a cooling pad help enough with this if it is the heat (the plastic knobs have also fallen off so it sits very close on my desk)? I have the latest nvidia drivers from their website but haven't updated anything else. I greatly appreciate any advice.

 

The GPU is flawed, it's happened to pretty much all of us.

Mines in RMA right now, we'll see what happens.

 

Does it have to be under warranty to have it checked out? And what do you mean by GPU flawed - because it overheats?