Are you sure your not trying to d/load fake files?
See
Recognising Fake files, also this post by LOTR:
http://www.gnutellaforums.com/showthread.php?t=63993.
Try d/loading a file from here and let us know how it goes:
http://www.magnetmix.com/audio2.shtml
@ UK BOb, Thanks for that prog. Tried it and my system is clean
.