Using an AT&T sim in an iPhone originally tied to a U.K provider

[Colin.B]

So my brother in law was stationed in England and bought an iPhone while over there. His carrier is vodafone and with his sim in the iPhone, it defaults to AT&T. He gave it to my mother in law and when I popped her sim in, it did not pick up AT&T as the carrier and it will not allow her to use it as a cell phone. I tried jailbreaking it and that did not work so I was wondering if there was any way to work around this and get the phone to recognize her sim. I heard about UltraSn0w but the modem firmware is 05.15.04 which apparently Ultrasn0w does not work on.

[Colin.B]

So I solved my own problem. I guess Redsn0w allowed me to change the modem firmware to a higher version found on the ipad which allowed ultrasnow to work its magic and now all is well in the world :).