I had a very brief look at the audio files. I used this program
to extract the files from the wavebanks. The .WAV-files seem to play without doing anything to them. The .WMA-files do not as bg says. Opened them in a hex editor and concluded that most of the start with the hex values 09 00 00 03 (I was looking at the MusicNew.xwb file). Also opened up some .WMA-files i had lying on my HD. Many of them has this byte pattern (09 00 00 03) at what seems to be the end of the header or the beginning of the data. I don't know exactly how this program (unxwb) extracts the files but maybe the .WMA-files are stored without the header and it needs to be reconstructed somehow? I don't know, maybe this could give some ideas. I don't have time to look into at it at the moment.