Random Shutdown/crashes

Ive had my white 2.0gHz Macbook since last October, for about a month now it will always randomly shutdown/crash and need a complete reboot (holding the power button down until it flashes and beebs) after each time I close and open the book itself. Usually about 2-3 mins after I flip the monitor up.

Ive tried the latest software/system upgrades hoping to fix the problem but to no avail.

Is there something I can do to fix this eternally frustrating problem or is it going to have to go back to the dealer for a service, I wanted to avoid this as I need my macbook everyday for university.

Is this a common problem? Is anyone else dealing with this?

Have you down loaded or installed anything in the last month? try this:

http://docs.info.apple.com/article.html?artnum=303319

http://docs.info.apple.com/article.html?artnum=2238

and if all elese fails, do this:

http://docs.info.apple.com/article.html?artnum=107120

I got $5 bucks that say's you have a fifty fifty chance of getting and x over your battery icon after you reset the pmu.