Info from both Quicktime and VLC helps. Since Quicktime didn't identify the audio, it does help prove that it's unable to decode the audio, vs being a problem where Quicktime is muted somehow.

Now I'm puzzled though why Quicktime won't play back the audio. If VLC is to be believe, it's an MPEG1 audio stream, though it's not indicating which exact layer. (MP3 music files for example are MPEG1 Layer 3). I only see mention of MP3 here, so maybe thats the issue. The audio is possibly MPEG 1 layer 1 or 2.

Very odd file, I've usually seen MPEG 4 H.264 video coupled with MPEG 4 audio. I'm not sure how to get it to play in Quicktime, and iDVD. :-(