Overheating problems! :(

I have a Toshiba A40-614(Specs in sig), which is very cool. However, recently the latop has been overheating more and more. The first time it ever happened was about 2 weeks after i got it, while i was watching daredevil . I got very scared and thought the whole thing was ****ed, but after that it didn't happen for about a month. Then It started to happen more and more frequently, at least 3 times a week. By then i had realised it was an overheating problem, and wasn't too bothered(happened after lots o use). If i put it in my lap, on the table, on my duvet cover,it would overheat and cut out completly in about 10-15 minutes. It was quite a problem.

About a month ago i purchased half life(i know, i'm late ), and started to play counterstrike. Straight away if i played and placed my laptop on the table, it would cut out. So i tried to improve the air circulation and stop the heat being trapped by elevating the back( I placed my AC adapter under the area where the usb ports are). This fixed it, and for 2 weeks everything ws good...I could even place the laptop in my lap and play. However recently, my laptop has been overheating/cutting out excessivly. By the time it takes me to start up CS, my lappy cuts out. If i try to watch a DVD, i get 20 minutes max. If i'm doing my HW, it'll go. For example, I was burning an avenged sevenfold cd through WMP, and while i was doing it, MY LAPTOP CUT OUT OVER 20 TIMES. I even tried placing ice under the hot air fan to fix it. It didn't help. Please help me! I need it too work I got a massive essay to do. Has anyone else had this problem?

My lappy is about 4 months old. When I say "cut-out" i mean the laptop totally stops. The power cuts off and the screen goes blank. There is no shut down "processs". It takes under a second. The hot-air fan is always boiling.

I'd love to open up my lappy, but it's extremely difficult to open. You can't take off the keypad, and there are at least 25 screws that have been screwed so tight it feels like theyve been glued in. I've even got my dad to try and take them out(he's a very strong guy). I've tried every type of screw driver going. I'm worried the metal has been grounded down around where the screw fits into place.

I'll take your advice on the spray duster(in fact i had already though of it. I can't find it anywhere. Any suggestions?) However there are very fine grilles over my fans and the dust cant really escape.