I have had my iPhone 3g for over a year. Last year AT&T updated the network to 3g, at which point I always had 3g throughout town. In the last several months, I have noticed that my phone will not pickup the prevalent 3g network in my city. I am always on Edge. I will compare my phone to my wife's 3GS and she is always on 3g. I have tried rebooting my phone, and even a clean restore, each time with no luck. Occasionally I am on 3g, but it does not last, while of course, her phone does. Do you think my network chip could be going bad? I no longer have Applecare...