Are you using the LW playlist in iTunes also or only wanting files added to iTunes?
Double-check the iTunes preferences advanced setting is set for Copy files to iTunes Media folder when adding to library.

I wonder if the Sharing section of iTunes would help, if it's not already set to share. ie: In iTunes preferences, check option for Share my library on local network. Does not matter which option of entire library or selected playlists as long as LW is included.

In LW check option for Share audio and video files on local network with iTunes. Doing this might also spring the transfer/copying of files back into action.

Are you using Java 6 or 7?