So I've noticed a very frustrating thing happening with my iphone of two months. On about 6 occasions after exiting an area without a cell signal (NY subway, basement of a building, etc.) the signal won't return. Zero bars, no Edge indicator or ATT indicator.) Nothing I do will return the signal and a reboot is necessary to get the signal back. Is this common or is my phone a dud? Also... call quality... coming from Verizon I was used to land-line-like quality, but the iphone sounds like the caller is covering up their handset with a wadded up tube sock. Very muffled. Again.. is this my phone or a "feature" of the iphone?