Why don't you try muxing your file in a matroska file instead? a mkv file should works better in what you want to do... you can even mux the original AC3 stream (unless you really want a low bitrate 2 channels only ogg/vorbis version of it). See www.matroska.org for more information

Fortunately, there is no reason to use OGM So if the muxer doesn't work for fragtal, there is no need to get headache about it.

omg I didn't expect so many ogm haters here... I've made tons of DVD rips using oggmux and never had any problems. Having another container flying around on my harddisk is not what I want. But maybe I'll just try to make an .mkv file...

In the link in my sig you'll find a document why OGM is crap. You'll see that the only way to handle it is to hate it, as a developer as well as a user.

A lotr rip taking 7 MB overhead in MKV and 52 MB overhead in OGM is more than hilarious...

Well, isn't matroska zealotry/propaganda a bit inappropiate reply for someone asking for help with OGM ? Please at least try to be helpful instead of just flaming someone's format choice next time.