1) Get a can of compressed air
2) GO OUTSIDE
3) Blow air into all vents/intakes, until no more dust and debris comes out

Step 2 is the most important one, BTW.

I did purchase a can of compressed air. I did go outside with my laptop and blew air into all the vents/intakes and completely dusted out the computer. I plugged it back in and (knock on wood) it seems to be running quieter, cooler and hasn't cut out and shut off.

Looks like your diagnosis was correct - it was overheating.

Thanks!!!!!

How big was the cloud that came out with the first puff?

As said above, try compressed air to clean it out - perhaps (just perhaps) you can upgrade fan - try to keep it elevated from work surface ( I used wooden pegs with a fan blowing air under it but it didn't work) or see if the chips are "hot" chips. When I had mine the chips were known to run hot and I replaced them - again, this didn't work.

It's possible, but rather remote, that you have a bad chip. Did you run a check on the chip integrity? Perhaps take it in for a professional check-up if you got a lot invested in the thing.

My sad story was that Toshiba had a lawsuit pressed against them and I settled for a partial refund for my experience with a laptop.

Good luck.

See article I posted earlier about hot running laptops and one possible solution:

http://www.democraticunderground.com/1018872071