No sound in WINDVD when film played from HD

[asterix]

Hello - downloaded a movie, have all the VOB, BUP and IFO files.

Plays fine in WINDVD and POWERDVD, but there is no sound.

When I try to play the folder in windows media player the whole thing runs fine with sound by launching the VIDEO_TS.IFO file.

No big deal, but prefer the quality through WINDVD. Anyone got any thoughts why this is happening.

Thanks

A