Just a tip, if you encounter something similar.
Today I had trouble getting some wav files to work with AM. I had recorded them with iPad, using iRig Recorder. No problem playing them with WinAmp in Win7, but AM did not play them in the sound preview when importing and threw an error at me when I had assigned the sounds to hotspots and ran the project. Needless to say, there was no sound.
Fortunately, I had seen this before, in WinXP, using a different piece of software, and with different audio samples I found from somewhere.
The trick is to open up the wav files in audio editor, I had Audacity for example, and save them. After that, they work in AM.
Apparently, not all wav files are created equal.