Have you accidentally deleted the playlist? It's like deleting your Limewire library - all too easy to do and that's what many of this forum's users have done. Check your Recycle Bin and if not in there, check your Limewire library and see if the files are still in there. If they are, make your playlist again. If not, you'll need to use a file recovery program (I think there's a thread about doing that somewhere in this forum - do a general search for 'File recovery').