I have an iPhone 4, ios 5.0.1, I jailbroke it with redsn0w and can get to cydia, I downloaded ultrasn0w (and the fix) to unlock it, shaved my SIM card to fit in the holder and it works fine, but for some reason I cannot get it to connect to the T-Mobile service. What else can I do? (switching to AT&T is not an option, it is not a hardware problem, how do I fix the software problem)