Dreamcast VGA box problems

[BurgerKingDiamond]

I just got a Dreamcast VGA box. The VGA doesn't work with my flatscreen (I have connected my computer through VGA to this TV before with no problems), although it does work with my room mates. Can anybody explain to me why my this is? I don't expect to fix it since it seems to be inherent with my TV (I got the box from Snaake, and he said it doesn't work with one of his TV's too). I am just curious as to why these TV's are being picky about which VGA signals to take.

The bigger problem for me is the s-video out that is also on the VGA box. This is the main issue for me because this is what I was planning on using it for. I have tried it with 2 CRT's which I know have working s-video inputs, through an s-video cable that I also know to be working fine. I also tried through s-video on a flatscreen.

On the two CRT's the opening dreamcast logo is still red, but the background is black instead of white. On one of the CRT's the picture isn't stable at all, it's kind of scrolling up and down and looks like total garbage. On the other CRT the picture is stable, but lined up way off center. I got absolutely nothing with the flatscreen.

I found some posts in other forum's with other people having the same issue of black picture using s-video. There weren't any helpful replies. Just the typical obvious stuff like "make sure the cable is working, make sure the TV input works".....

Can you help me?
BKD