I use this free program,
DVDVideoSoft, to convert DVD's to AVI so I can play them on Express Scribe. They also have audio conversion in the bundle or separately. So although the WAV file should play you could try converting one of the files to MP3 or something else to see if that helps. I've never used the audio conversation, but the DVD conversion is fantastic.
Hope it works out soon for you; I KNOW how frustrating that can be!!