You can look up files before download with Bitzi, if the file's been rated then you'll have some idea of the content/quality
Bitzi

If the preview button's not working, maybe you need codecs for your player. Or you can try VLC, it's free & comes with built in codecs.
http://www.gnutellaforums.com/showth...ght=wmp+codecs

It might have been a good idea to get these sort of problems ironed out before buying Pro