When I add a wav file to the audio tracks and try to play it I get a very strong noise that "cover" almost completely the song. If I play the same song with Amarok the quality is good. Then the song and the audio hardware seems good.
I had the same noise also playing just a photo in video track and no audio in audio tracks. I installed Cinelerra 4 (a video editing software) from "Software manager" (PLF repository) in Mandriva 2010.0 Power Pack.