OK, I think I know what I did wrong, so just for the benefit of anyone else, here is how to prevent the problem. When you first define a scheduled backup job you should always specify Full Backup. Then, after it’s had a chance to run one time, you can edit the job’s properties to make it Incremental or Differential for future runs. In this way, BackItUp recognizes that the job has already run once, and it can proceed with the smaller daily updates that you wanted, rather than starting all over with a full backup each time. Does this sound familiar to anyone?