If the sound does play in other movies, and these movies give sound in other programs (like VLC player), I'd try with their codec pack.
If no luck, contact their tech support or try another program. All you lost: $4.99 for the codec pack.
Kees
I hope this ise right forum. I am using Movie Plus stater Edition and I have imported files which are in Mpeg format, but now they are playing without any sound.
Can someone explain how to fix this please?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic