Screen Problems

[eperry2011]

Hi! I have about two years of overall *nix experience, but I just recently purchased a new laptop (Compaq Presario CQ-50). In particular, there are two distros that I like (the *buntus and Mandriva), so I have either one of those and XP in a dual-boot setup. Problem is this, with either one, I can install everything and all is well, but randomly while I'm in the middle of working normally, I'll do some random event (i.e. go to the address input bar to type something in), and in the middle of typing, the screen starts to block up. If I Ctrl-Alt-Bksp to restart X, everything restarts again, but it'll happen again within 5 minutes, and if I don't restart X quick enough, the whole thing locks up. Sometimes I'll even have my Caps Lock flashing as if there is a kernel freeze, but how could the kernel freeze so randomly? What's causing the random problem? Solution? My rig has a NVidia card, so I install the card's drivers directly from the website b/c they work better & faster. Any help would be appreciated - thanks!

Processor: AMD Turion 64 X2 RM-70? (2 Ghz)
3GB RAM, 200GB HDD (SATA, I believe), NVidia GeForce 8200M G Video Card, running Ubuntu 8.10 or Mandriva 2009.1 and Windows XP Pro