3D Screensavers start out fine, then stutter and halt? (No virus)

[Tailgun]

Sometime after reinstalling my OS, all my screensavers start out fine but eventually stutter badly and slow almost to a stop! This had not happened before and I cannot determine what is causing it.

I have updated to the latest version of DirectX and updated my NVIDIA drivers to v175.19. This is a fresh WinXP Pro install and there have been no virus infections (just scanned again with ESET to confirm).

What can cause a 3D screensaver to start out fine, but "wear down" over less than an hour - until it is barely moving?

My stuff:

Dell XPS Gen 2

NVIDIA GeForce Go 6800

Intel Pentium R 2.13 GHz

2 GB RAM

DirectX 9.0c

Thanks,

John

"Nobody can be exactly like me. Even I have trouble doing it."