The Dink Network

Some wav files contain extra non-audio data such as author and copywrite information. For some odd reason, Dink requires this data to be there in wav files over a certain length. Some sound editors can put that information in for you so it works.

You can get a time-limited demo of such a program here:

http://www.syntrillium.com/download/

That might solve your problem, but there's probably other things that could be wrong.