Which version of LW are you using?

Are you downloading the movie from the gnutella network or is it a torrent?
LW isn't a good torrent client (has issues with tracking share ratio, lack of options & is even banned by some trackers). Most people here would recommend Vuze or uTorrent

If you're downloading a torrent, did you check for comments about the file before download?

If you're downloading from the Gnutella network, have you checked the file with Bitzi? How to use Bitzi
If there's a corruption within the file then download % can fluctuate & go backwards: http://www.gnutellaforums.com/frostw...wnloading.html