I recently switched a couple of Verizon Samsung Galaxy S4's to AT&T. They were already unlocked. The problem now is that all incoming calls have a + sign in front of the phone numbers in the caller ID. Not sure how to stop this from happening. It causes problems with sending a text to the same number that calls, because the SMS system does not recognize numbers with + signs. These are not international calls, they are domestic calls. I don't know if this has something to do with the fact that the APNs are now connecting to AT&T's HSPA+ network. Any ideas on how to stop this? Has anyone else done this and had the same problems and been able to resolve it?