I just started using True Image Home 2009. I'm backing up files, differential backups, through a home network to a USB external drive. When I backup a large folder (about 8 gb), it automatically creates two backups. The second backup is created a few minutes after the first, and is smaller in size. Yet, when I open the subfolders/files of both backups, each seems to have the full set of subfolders and files. What gives? Any ideas?