I recently upgraded 3 lines to iPhone 5 from iPhone 4. All three of them are dropping calls where the iPhone 4's did not. In one particular building, the iPhone 5 doesn't get a signal at all, where the iPhone 4 worked fine. Also having an issue where iMessage occasionally works on one of them, but most of the time does not. Is anyone else having these issues? I've reset network connections, restarted the phones, removed SIM cards. I'm at a loss. How can a phone with more antennas be worse? Never had issues before.