Hello, I have had an iPhone 4 for a while now. I've unlocked it using UltraSn0w. The problem is that quite often the network on my iPhone just disappears. There's nothing repetitive about it. I mean it happens anytime, anywhere. I really need help because it is really affecting my business. Talking to people one sec and then the other second the network's gone, and it takes sometime as long as an hour to get it back. Which becomes very frustrating. I have to constantly restart it and take out the SIM and a lot of other stuff too. Any help ? Please ?