Need to rip audio from menus

[jmelly]

I am trying to rip the audio (AC3) from a DVD and using the demux tool in ffmpegX in order to get to it. However, when I do I get 3 files: VIDEO_TS.VOB.0.ac3, VIDEO_TS.VOB.#0.ac3, and VIDEO_TS.VOB.0.m2v. The AC3 decoders, including quicktime (using Perian) choke on it, so I think the file being output is bad.

Does anyone have any advise how to rip the menu audio, or suggest an AC3 decoder? I have been posting at various DVD sites and am not making much headway on this. Any help would be greatly appreciated.

[Case]

Please check the file sizes. The main menu is usually in VTS_01_0.VOB, as VIDEO_TS.VOB is usually a very small file.
I just verified this on the Narnia DVD, and ffmpegX's demuxer does a good job on it, as well as Perian's AC3 decoder in QuickTime Player.
Depending on the specific title, there might be other issues, though.