Just as an experiment, try downlding some audio files from the magnet links here http://www.magnetmix.com/index.shtml Are these ones corrupt also? I think these are all wma I'm not sure (I hate wma with a passion!!! lol )

Oh I just realised you're a mac user. If you don't have mac's wmp then go for VLC - (click on link) _ (choose nearest mirror site) to playback the wma files.