9600GT S-video problem

Well... I have this S-video to RCA cable i used to connect my computer to the tv and watch DVD's in there, i used it with my ATI 2600PRO and it worked amazingly well, then i formatted my computer and it stopped working, but if i uninstalled and reinstalled the ati driver it would work again, but only once, i could actually see Video image in my tv, but it was black and white and it was like coming up and down.

Now i formatted my pc again and i bought a 9600GT and i cant still use my TV, tho its different now, i see good video image in my tv, but only for a secondm (even tho Nvidia driver says i have configured it correctly and i can take the ouse pointer out of my monitor indicating the secondary screen is working, sort of).

I know its not my TV, since i use it once in a while with my Wii and not the cable either, since i have used it with other computers, when i had the ATI it was in XP, now im using W7 and taking advantage of DX10, i still have no clue of waht's going on and if this hapenned to any of you please explain me.

Anwyays, any help is welcome Thanks.