Apologies for resurrecting this thread, but I recently got hold of a 2nd copy of Beowulf (also brand new) on HD-DVD.
It displays the exact same intermittent stuttering
So, either i'm incredibly unlucky and have bought 2 faulty discs or more likely, my 360 (or it's HD-DVD drive) are incapable of playing back this particular movie.
The 360 is the newest Jasper revision, and has a net connection - so is fully updated.
The HD-DVD drive is.... well an HD-DVD drive, i'm not aware of any firmware updates, or different revisions ever being made.
It was bought 2nd-hand from Gamestation.
To satisfy my curiosity I think i'm going to put a little more effort into getting a 2nd HD-DVD drive; having a spare is never a bad thing when you have a collection of almost 200 HD-DVDs
However, in the mean-time I'd like to see if my PC is able to play the beowulf disc - can someone point me to an accurate guide for achieving this?