S-Video black and white.

I have an issue with the s-video in. All seems to work well but one of our dl2 is in color and the other is in black and white. Pics looks ok. When the image is split you get a great stich but one color and one isn't. Thoughts please help have a gig on Friday if possible. Thinking reinstalling the software but then how do I get stock media back.:confused:

Both have the same settings on the hardware input screen and are both set to ntsc ml. I have changed the internal input leads and still black and white I have also plugged the svideo direct to the input and still no joy.