Any chance that you might have just moved the files? Use your computer's search to look for some of the file names.

If you've deleted files fom LW's library, they'll be deleted without going to the recycle bin, unless you're using the latest beta version. Have a look at the sticky below for some file recovery advice
DELETING FILES FROM LIMEWIRE LIBRARY-DON"T! - File recovery advice!

*LW 4.13.0 beta sends files to the recycle bin if they're deleted from LW's library.
http://www.limewire.com/english/content/download.shtml