If PA was just recently added to the list, its possible that its not "up and running" yet  When CA first got added to the list, it was 6-12 months before it was actually "working"

I do know that when I EF a CA Amended, it gives me an error and tells me the CA EF box (for the original return) cannot be checked if Im EFing the amendment....could that be the message youre seeing?  That it wants you to uncheck the EF box for the original PA return?