Yikes, sounds like a stressful one! First stop would be
WAV Saver if you haven't tried it already. Beyond that I would try the scatter-gun approach and just load it in every audio playback device/software you can find. I once had a file that opened for some reason in
Goldwave and nowhere else. Got decent playback of a wonky file on my flash recorder once too. Quicktime Pro and iTunes sometimes have flukey good luck as well. Pass along the solution if you find it!