Hello, I have a Canadian iPhone 3G (original carrier: Rogers), which I have unlocked. I've used the original Rogers SIM, and since unlocking it have used a Vodafone New Zealand pre-pay SIM as well as a Rogers pre-pay SIM. I am in the US on holiday, and have purchased a GoPhone. My GoPhone works fine, and my iPhone works with the Canadian pre-pay SIM (not the original SIM). It also works when I put in my New Zealand pre-pay SIM. However, when I put in my AT&T GoPhone SIM, it doesn't work. I get the No Service indicator, and it will not connect to any available carriers (currently AT&T and T-Mobile). Also, in Settings -> Phone, it does not show my phone number. Any ideas why this won't work? I've tried rebooting the phone by holding the power and home buttons, numerous times. I've switched back in my Canadian and NZ SIMS and they continue to work, but I can't get the AT&T SIM to work. Thanks.