maybe it really is overheating and maybe you need a better fan? and/or - did you try opening it up and using a can of pressurized air to blow all the dust out?

I`m always a bit apprehensive to do anything physical with then notebook because if I screw it up, I pretty much have no back-up. At least internet connection would be a bust. However I`m hoping to get a new computer (or rather older one from someone else) by next week so maybe then I can have a technical-savvy friend give the notebook a once-over. Le Sigh, it`s always something with this thing.