Build 6514-Reappearance of deleted empty folders

Build 6514
When selecting the software option in the back-up and recovery section (see one attachment below of how I did the deletion-used whole back-up delete option), I successfully deleted some older full back-ups that were stored on a USB external hard-drive that I no longer wanted. After doing that I manually deleted the empty folders that still remained on the external drive. However, from time to time and without any understanding on my part, the empty folders are re-appearing on the external hard drive, and another USB flash drive, where I once made a single back-up. I think it happens if I select the search for back-ups option. It seems to be remembering all of the history, and then replacing the empty folders that I deleted. How do I stop that? Win 7 32 bit Pro OS.
Thanks!!!!
PS-After posting this note on the forum, I subsequently tried the mount and dismount image feature. When I did that, most if not all of my prior full system back-ups appeared in a list (see screen capture of many of them), yet they were all deleted in the past as discussed in the method above.