I think this is related to my problem, although my movies freeze within the first 10mins and at the end. Some discs are that bad at the beggining that the player rejects them. I have a 851s on secondary master with and MSI DVDrom as slave. I now have around 30 coasters 2 discs from an entire spindle actually worked?!!?!?!?!
I have tried switching master and slave, defferent media, new ide cable, reinstalled XP, taking off the slave drive, flashing to gsoh, 4 different burning packages. I am now ready to return the drive I think, too many hours trying to resolve this instead of enjoying my movies.