this is a common one
some files don't seem to like launching from limewire
go to your system folder/ preferences /shared and take the files out manually
then put them wherever you keep your mp3's.

personally I put an alias for my shared folder into the apple menu items
cos it makes them easier to get at. also I don't share my shared folder just because I like to check files before I share them(just in case they are faulty)