Michael,
I believe that would be the Nvidia GeForce FX 5800 Ultra board that ain't to fond of screensavers. They seem to get 'em a little hot around the collar.
You can read more about it here:
http://www.megagames.com/news/html/h...ensavers.shtml
or here:
http://www.pcekspert.com/articles/127-1.html