If you Develope app for Symbian Anna as Selected Device then We can't publish app for 3rd edition.
Make Sure 3rd Edition SDK is added to Qt Creator and While Creating New Project then Select for 3rd Edition instead of Symbian Anna.
Because if you Develope app for 3rd Edition Mobiles they work in latest Mobiles like Symbian anna or bella. If you Select Higher version as Development SDK then they will not Work in Lower Versions.