I use dvdsanta and have come across this problem a few times...
Its one of the files and now you need to work out which one it is if not all 3..
You can start by checking the file on Bitzi
http://www.gnutellaforums.com/showthread.php?t=37676 info on how to use Bitzi...
I have also done what Aaron has suggested deleting the app and re-downloading it and I have fixed the problem that way, but when it continues to happen it has to be the file...
What happens to your shared folder (outside of LW) when you open it to access your files???