Now I've done it...  I upgraded a prefectly working MCE 2k3 machine to MCE 2k5 (discs from MSDN Subscribers Download), and now I'm horked.  Well, kinda horked... 

I flattened/paved the box, and did a clean install.  I updated my nVidia GeForce3 drivers to the 10/15/2004 drivers.  I purchased the NVidia MPEG decoder.  I tested this setup w/ WMP10, and DVD playback is fine.

When I start Media Center, it lets me choose "Live TV", then the little spinning arrow goes for a bit, and freezes.  The TV screen is black, and there is audio coming from the proper tv station.  I can change the channel, and the audio changes fine, and there is no video.

Same for DVD.  I click on Play DVD... The UI still shows the scrolling menus, and is frozen.  Once again, the audio is playing fine.

I'm sure I dorked up one of the various video drivers, and I can't tell which one needs to be fixed...  Anyone have any ideas?