hmmnn.. can only recommend watching the thing all the way through (or rather leaving it on play and returning every 15mins to see if the synch probs are on the downloaded file itself).
Other than that m8 - try www.dvdrhelp.com or the doom9.org forums - sorry m8.
When I used to have similar probs I updated everything - the standlone dvd player firmware, my dvdwriter frimware, the divx player codecs and updates, and let it connect to the internet everytime it wanted to (firewalls can be a bit picky with media players etc)
Cool pic sig btw