There are a couple of scenes where dialogue is clearly missing. The most notable is around the 1 hour 50 minute mark where they're having an argument. Mark Wahlberg's character walks out, just as he leaves the doorway you see his lips move, but only fainly hear him say "piss off" or something.

I've tested this on my HTPC and desktop PC, with PowereDVD 8 hacked to play HD-DVD's.

Just wondering if this is an issue with the mastering of the disc, or my software/hardware.

The problem persists on both the DD+ and the other audio format, whatever it is.

Sounds normal to me (Marky Mark murmurs "piece of sh..." as he leaves the room). Perhaps a problem with your center speaker level?

I don't think it's coming from the centre. It's very very faint to hear, no where near as loud as the talking leading up to the scene, or after it.

Maybe PowerDVD8 is screwing up somehow? Seems odd that it's exactly the same on two computers.