Fullscreen TV-out video crashing system?

[Guest karatestarfish]

I've come across a problem while trying to watch videos on fullscreen on the tv out. Intermittently, the picture will freeze, and the computer will be unresponsive for about 10-20 seconds, after which the blue screen will show with an error in nv_disp.dll. The sound will continue until the bsod comes up. Occurs using multiple playback programs, multiple videos (different codecs) but doesn't seem to occur if the video isn't displayed full-screen.

The computer:

Dell 5150 (Bios A33)

NVidia 5200go

driver 71.89 (also used 67.66, 66.31 with the same result)

Windows XP Home SP2 with all updates installed

DX9.0c

I've just tried using drivercleaner to remove older driver versions etc, so I'll have to see if that works. Is there anything else I could try? Any options that might be worth switching off? The card is manually overclocked at default freqs (I overclock while playing games) I've never had any problems while running games for extended periods of time - just while playing videos.

Any ideas? I can't think of anything that might cause problems that I wouldn't expect to also occur while gaming...