Well done on such a great application!
I found posts stating there is an issue with incremental and differential backups with multiple directories selected. I have gotten the same error with a complete backup as well.
move file error
Cannot create a file when that file already exists.
Locations=|Z:\\General Documents\\Steve G\\QM Stuff|Z:\\General Documents\\Steve G\\Possible Tenders
Hope this info helps... Is there a work around I can use for doing this??