Oh, sorry, missed the bit in your gconf settings where you have it backup daily. This will cause DD to make fresh backups every 2 weeks (it scales according to how often you backup, so as to keep not too-long chains of incremental backups).
But the rest of my questions remain. In particular, do you let the fresh backups finish? Because DD will keep trying/resuming a fresh backup if it gets interrupted.
Thanks for the bug report, BTW! :)