I've been putting a good deal of time into ripping some Star Wars DVDs so I can watch them on my Xbox. Unfortunately, things don't want to cooperate. First I encoded everything into an OGM container using xvid4 and vorbis for the two english tracks (5.1 and directors commentary). This wasn't ideal since I found out that vorbis doesn't encode 6 channels. So I decided to do AC3 passthrough for the first track and voribs for the 2nd; well, that didn't work as described either.
Several revisions later, I found a combination of FS mount paramters (giving bad permissions), using xvid instead of xvid4, explicitly setting the audio track options, and disabling PSU core seems to be keeping the A/V in sync and producing OGMs with two audio tracks. I'm ripping all of Episode 4 (4th time); so here's keeping my fingers crossed!