I have a 8Gb iPhone 3G and I jailbroke it, and Im having some reception problems. I get the NO SERVICE display even though there is reception and to make it work again I have to restart the iPhone and the reception is back, eventually (after a couple of hours) the same thing happens, so the same process. I already restored as a new iPhone, made a reset from the iPhone Erase all content and settings, and changed the SIM card for a new one. Ive checked with friends with iPhones and they dont seem to have that problem. So, is there anything I can do to solve the NO SERVICE? Or how can I delete all traces of jailbreak so that the Genius Bar personnel dont detect it, and void my warranty?