I've just started packing my first new rig and going throught the same dramas as everyone before me. From what I understand the dbag is part of the container and not the part of the canopy. It's sized so that when you put the canopy in it it will be roughly the right size and shape to fit the container, changing the dbag will just swap one problem for another, ie closing the container.
I'll wish you luck if you wish me luck in return!