I would want the Roxio apps to play audio from the AUDIO tracks, rather than trying to play audio from the VIDEO track in the .mpg. Maybe you're unaware that MPEG, AVI, MP4 and all other video files contain two tracks.
I'm using; Media Player Classic, Cineplayer, VideoLAN, Winamp and Video Redo. All work just fine.
I've already done what you suggested and even used http://www.ursoftware.com (Your Uninstaller) to completely wipe it out on a second attempt.