OK, I need to ask this... why disable TV-out?
I'm sure that the error in playing DVDs is something that can be fixed. Think about it: Microsoft wants to sell you Windows XP Media Center PCs, which should be replacing DVD players... do you think that DVD copy protection initiative would stand? Something will get fixed, and soon.
As for other reasons, I cannot figure out why didn't you people buy non-TV-out cards, if you really don't need it, since they cost a premium...
Sorry I can't be more specific. I have a Geforce2 with VIVO, and I toggle between the monitor and TV with a simple key combination... but I don't know what your cards offer...