Asus g51vx-x3a Crashing

I need help with my Asus g51vx-x3a, which has recently been crashing very often. The screen flickers and the machine locks up, though it appears that background programs are running. I few factors that should be mentioned, I overclocked the processor from 2.53 GHZ to 3.0 GHZ a few weeks ago, I've been running the machine at stock clocks most recently though. The computer does run hot up to 100+ degrees, though this hasn't been an issue in the past, and with the use of my Cryo cooling pad, it peaks at around 95 now (this is under intense GPU load, games, etc). I reformatted the machine two days ago, so I doubt it's a driver issue. Thanks for your help, my system specs are listed below.

Asus g51vx-x3a:

Core2Duo: 2.53 GHZ Processor
Nvidia GeForce GTX 260m
4 Gigs RAM.

 

What does the flicker look like?

Have you overclocked the GPU?

What are your exact idle/load temps?

Have you tried reinstalling or upgrading your nvidia drivers?

 

I updated my video card drivers, and did a temp monitor, idle temp is about 75 for the CPU (yes I know it's hot) CPU is around 45 (not OCed)

After the update the computer still crashes, but two black bars flicker in the screen momentarily before the computer locks up completely.

*Idle temp for the GPU is 75 degrees.

I'm doing another thermal compound reapplication, I see that there is a third chip under the heatsink, CPU, GPU, and this other chip, do you know what this is?

 

That's the PM45 northbridge chip.