I had this problem!
The answer for me was... *drumroll please*....
I took out the 128 MB stick that came with my computer, and put in a 256 MB stick I bought from Future Shop (it was 'Azen' brand... probably cheap stuff... but I bought it there because they have a 30 day return policy just in case it didn't fix the problem).
Anyways... with the new 256 stick of RAM, my computer does NOT crash anymore!!
Give it a shot!