Re: Black & White TV-out (FX5200)
B/W picture on s-video usually indicates a bad cable. The difference between composite and s-video is that the color signal is separated from the image on s-video. B/W would indicate no color info is being outputted or getting through.
I've got my TV hooked up to a freebsd machine with an FX5200 using an s-video cable. Color's just fine. Don't even have anything special settings in my xorg.conf. It's just a plain conf.
Edit: One more thing that popped into my mind. How's the s-video connected to your TV? Using an s-video connector or an s-video->scart converter? I use an s-video->scart converter to feed the signal into the back of my TV. I've got 3 scart inputs and they all handle scart a little different. Not all scart TV inputs can handle the s-video signal. Check your TV manual. You may also need to switch your TV from scart/composite to scart/s-video input (check the menus on your TV).
Having said that the picture quality isn't that good and I'm thinking of building an vga -> rgb scart converter. My TV accepts rgb scart signals and it would probably improve the picture quality. IIRC the FX5200 is capable of producing the correct timings to pull this off. AFAIK not every nvidia card is able do this.