You have probably downloaded a bogus file and then see copies of that same bogus file, given other names in your search results. i.e., you downloaded what you thought was X, but it was a bogus file. You later search for Y and see the same bogus file (this time labeled Y) so LW says you've already got that file.

Could also be that some songs in your search results are simply mislabeled. This is common among songs by the same artist. You think you're getting 5 different songs but you end up with the same song mislabeled 4 times. And if the hash is the same, LW will say you've already dl'd it.

Some help here: http://www.gnutellaforums.com/open-d...uld-aware.html