I made some tests and from a technical point of view it's all correct. The error with i_pod.fsb can be ignored at the moment because the files are dumped correctly.
They are 6 channels mp3 that fsbext downmixes to stereo, but it's not a real downmix because it simply dumps 2 of the 6 channels (fsbext does NOT modify the data). What you see is a very low volume so I decided to: 1) dump all the frames instead of only those of 2 channels 2) dump the raw mp3 with the -m option
The result is that it's really low the volume and it's not a problem of fsbext. The mp3 is complete and sounds exactly like the one you posted if you normalize it. So it's all ok.
The normal mp3 files can be just mono or stereo so you can't put 6 channels in them and this is exactly what fsbext does by default: dumps 2 of the 6 channels.
Anyway I have an idea that could solve the problem and will allow you to put every single channel in Audacity, basically for me would be enough to dump each channel in a separate mono mp3. I check how to implement it because the functions used in fsbext work in a different way.
*bump* sorry 'bout that, but the game splits the 12 tracks (one left and one right track for each ingame track) into two files containing 6 of those tracks (3 ingame tracks)