Before T-Mobile supported the iphone, I bought an unlocked and jailbroken iPhone 4. I'm pretty sure that the original carrier was ATT&T if that matters. Do to the unlock and jailbrake, I am stuck on iOS 5.1, and I would really like to update my software. However, if I update it, I will lose the update and the jailbrake. My question is, since T-Mobile now supports the iPhone, including iPhone 4, is it possible that I could update its software and still be able to have service with T-Mobile? Thanks in advance.