The work around is to open the original wav file with audacity and then File->Export as WAV. The resulting wav file is about four times as large, but is in a usable format. From there use your favorite tools to create an OGG or MP3 file.
It appears the problem has to do with the way the MuVo encodes the wav:
VOC001-original.wav: RIFF (little-endian) data, WAVE audio, IMA ADPCM, mono 8000 Hz
VOC001-clean.wav: RIFF (little-endian) data, WAVE audio, Microsoft PCM, 16 bit, mono 8000 Hz