One of the profiles I have created backs-up a folder whose contents are important and which are subject to a lot of changes. I set the backup interval in the profile schedule to be 30 minutes. Unusually there have been no changes in this folder in the last 24 hours, but BIT has created an incremental backup, on schedule, since then which contains just a single file - the same file every time. It is not a file I can change because it is password protected and I do not have the password. I have compared every incremental backup version of this file with the original, using the diff command. No change is detected in any of the incremental backups. Why it BIT selecting just this one, unchanged, file in each incremental backup?