If I have a node with a file being harvested from a cck filefield, and I delete the file, but do not delete the node, the file is NOT removed from the media_mover_files table. Likewise, if I replace the file with a different file using the CCK filefield (ie remove file, then upload new file), the new file will be processed by Media Mover, but the old file will NOT be deleted from the media_mover_files table, which it should be.