Geforce 2 TI and XP no TV out put please help!

[ThreeLeggedGnome]

I upgraded my OS to XP about 3 weeks ago, went in a few days ago trying to play some mpeg's through my TV output and it's not working anymore. When I choose TV under device selection the OS can see my HDTV and my HDTV can see the s-video from my geforce2 TI. When i click ok to switch output device both my monitor and TV flicker momentarily then it goes back to my monitor instead of starting to display on my TV. I'm baffled. It worked great before under win98. Any suggestion? any help is appreciated.