I'm getting a somewhat similar problem, except that commercial DVDs simply won't play at all in Media Center, WMP, or Media Player Classic. I put the DVD in, and try to load it up but the players just don't respond. They don't freeze or crash but there's no menu, no video, no sound.
I thought it might be a problem with the dvd drive itself, but dvds manage to play reasonably fine with VLC, and its not like the OS isn't recognising the disc in the drive.
I'm pretty much at the end of my wits with it. I've tried downloading mpeg2 decoders, codec packs, or searching for anyone with a similar problem and this thread is probably closest to mind I can find.
Anyone have any ideas?
btw: gtx 295, pioneer dvd r/w drive, using the windows7 64bit beta (build 7000) but downloading the RC now in hopes that it's fixed.
All drivers are up to date too.