The manner in which AR 2013 prints backorder invoices needs to be changed.
There is no logical reason for the backordered product to be listed with a zero quantity and zero value then listed ag...
See my post on this topic in 2012 here: http://community.myob.com/t5/Upgrading-to-AccountRight-2013/When-backordering-on-invoice-information-is-duplicated/m-p/104185/highlight/true. Not sure if we had an ideas board back then. Thanks for raising it again, I've voted.