I sent My(2)Cents an email with some things to look at, but for the benefit of the forum, I'll repeat some of it here.
I have never seen a primer go in upside down on a Star, but I could see how it could happen if the primer magazine was not fully seated in the primer magazine socket. The bottom of the primer magazine should be nearly flush with the bottom of the primer magazine socket.
The instance where a primer is not loaded is generally caused by a dirty primer magazine or primer slide, or a burr or some sort of damage at the bottom of the primer magazine. You should be able to drop a primer in to a primer magazine and have it drop all the way through without any resistance.
Bruce Williams
Star Machine Works