There have been reports of newer players having difficulty with new DVDs, with effects like the sound cutting out, etc. I know this is the case with, for example, Jurassic Park 3.

You could check forums on dvdtalk.com or dvdfile.com to see if other owners have noticed the same problem. If you're not happy, I'd take it back, or at the very least contact the distributor/studio and get a new copy.