With the new 1.14.09 firmware, my old DVR-MS videos generated with Media Center in Windows Vista are now playing with correctly sync’d sound - hooray!
The bad news: DVR-MS video generated using Windows 7 built-in WTV to DVR-MS converter only play for 3-7 seconds before dropping out entirely back to the file browser. Sounds similar to the problem reported in an old post:
For that matter: how about the capability to play WTV files on WD TV Live without conversion?
DavePi