New DVD - No Sound

I purchased a new DVD from Dancevision and my Dell laptop does not play the sound.  The DVD plays normally on my NAD DVD receiver.  This is the first DVD I am aware of that doesn't play.  I have Dell 1525, XPSP3, WM9 with Corel DVD Pack.  The DVD has a 2004 copyright so it's not a new format, and I have many other DVDs from the same source that play normally. 

Any ideas why this laptop will not play this DVD's sound?

Thanks,

aquaries