The first clue was my thumbnails were green with a band of static on it. I've always used the MPC included in CCCP which didn't have problems playing back the video clips. Portable VLC has its own decoders so it never has a problem. Windows Media player didn't work despite having a copy of Morgan installed. What I had to do was enable MJPEG in FDDShow for VfW. Vegas and Windows Media Player needed a VfW drive.
Start -> Programs -> Combined Community Code Pack -> Filters -> FFDShow VFW Codec Configuration
Decoder -> Codecs -> MJPEG -> libavcodec (from disabled) -> Apply
Decoder -> Codecs -> Other MJPEG -> libavcodec (from disabled) -> Apply
Reboot your PC.