LW is telling you that you already have the same exact file as the one's that show up in your search, even if it has a different name. LW doesn't go by filenames, it uses the file's "hash" identifier. So even if the name says it is a different artist or song, LW will recognize it as the same file.

At the risk of downloading identical copies of music you already have, you could move the songs to a different folder before starting your search.