It could be a heat issue! Open up your case and make sure your processor heat sink is not caked with dust. Same thing happened to me once and it was the heat causing the shutdown.
Lazslo, I have a water shot from Nassau, Bahamas. It’s probably exaclty what you are looking for. If you are not too much in a hurry I can email or ftp to you a 10sec. sample that you can loop.
I’d like to be one of the testers. Check my profile for video system specs. For your audio plug-ins I can test them in Cubase SX. For the video plug-ins I use Vegas4 (one of the few still using 4 just because I can do my work and don’t need the upgraded features of the newer versions)