"FBackup does not keep track of previous backup versions.
Only the latest version of the backup is stored in destination."
This totally sucks, but it answers my question. And here's why it sucks. While trying to do a restore, I accidentally started, then immediately stopped, a backup. So the program thinks this is the latest back up - which is empty. Now, because of this stupid inabilty to restore anything other than "latest version of a backup," I cannot restor my actual, latest version of my back up. I can see it, but it won't let me access it. Just great.