So I sold an unlocked iPhone 3G to a friend of mine. She went to Virgin, got a SIM, popped it in, but they said that she wouldn't be able to receive calls; something to do with Virgin phones that use a SIM.
Sure enough, she can call out, and can send and receive texts, but whenever anyone calls her, it does a fast busy signal, as though it's off the switch.
When she first phoned in asking if she could use an unlocked phone, they said that she couldn't because it would "break the phone".
When she got the SIM, they said that she can't receive calls "because all the cell towers aren't built yet officially". They claim that an iPhone brought to them won't work because it uses different towers.
Does anyone know anything about this? As far as I'm aware, the 3G should have the necessary hardware, and it certainly makes no sense that she could call out, but not receive calls.