At my company we use lots of Dell Lattitudes and constantly have problems with over heating, hard drives crashing, and mouse cursors moving by themselves. All problems that Dell is aware of on the older c500s and c600s but didnt resolve because of their new line not having them. I would bet that your issue has to do with over heating of the processor. Just a guess but if the bottom of the laptop gets very hot just before it BSOD's then this is the issue.

There are attachments you can buy to resolve the over heating issue but I would just get a new laptop if I were you.