As I said, if you restore from a backup you will lose the link between your online tree and your FTM tree. I can't upload a new tree from FTM to Ancestry.com, because I don't want to lose my family's invitations and have all my reviewed tree hints reset; so I only download from the Ancestry.com tree to FTM. This makes using the backup impractical. If one could restore from a backup and have that tree stay linked to the online tree, that would be a different story.