I just received my GPP Turbo and it doesnt seem to work. I have an AT&T 4s with 5.1. I inserted my non AT&T sim card using the GPP tray and interposer. It will start scanning and will show no service then after a minute or two, the phone will reset and activation is required again. Ebay seller advertised that it's supposed to work with 5.1. Any thoughts?