Media Player Classic just saved the day.
After WMP9 started spitting out errors when trying to play MPEG video files and VLC could only manage audio-only, MP Classic worked.
Here's some bumf from the download site:
Media Player Classic is an enhanced version of Media Player 6.4
Freeware | 2.12MB
Media Player Classic looks just like Windows Media Player 6.4, but has many additional features. It has a built in DVD player with real-time zoom, support for AVI subtitles, QuickTime and RealVideo support (requires QuickTime and/or Real Player); built-in MPEG2/SVCD/DVD codec.
It also supports SVCD/CVD selectable subtitles and lots more. The best part about Media Player Classic is the ability to modify the filters when playing your favorite video files."