To resolve this problem please use “Redemption Backup Store Groom Tool” which can be used to delete the existing old Backup stores.You can download the above tool from the following URL:
http://www.techsupportlive.com/index.php?_m=downloads&_a=viewdownload&downloaditemid=57
To know more about Redemption Backup store groom tool please refer to the document available in the following URL:
http://www.techsupportlive.com/index.php?_m=downloads&_a=viewdownload&downloaditemid=59