I have had my iPhone 4 for about a month after the initial launch. Didn't get a bumper for about a month after that. In that one month time frame, I did not experience a whole lot of the dropped call issue. Lately, for about 2 months now, if I am calling someone, the call will somewhat "drop". They cannot hear me, but I can hear them perfectly. This happens with every single phone call I make now. I have tried everything from removing the bumper, to even turning off wifi and 3g and talking in Edge. It does not matter it seems, and every call, the person on the other end cannot hear me. I live in Phoenix, and ATT has decent enough coverage that this should not be happening. Anybody else have this problem, and hopefully a fix?