It could be to do with the names of your files.

When downloading a file you look to see how many people are sharing it and usually select the one with the most users, that way you connect to more hosts and have faster download speeds.

If you have files named 'well' and 100% correctly ie. artist-title you may be the only one sharing that file, as if you notice on limewire a lot of files will be named t648492_artist_title etc.

Limewire for very good reasons does not associate files together which are the same size and have similar names.

I noticed this when downloading movies, most of what I downloaded had stupid letters or numbers in the file name. when I renamed it no-one downloaded the file. If i kept it exactly the same they did!