While the iPhone 3G has been selling millions of units around the world, a small but vocal percentage of customers have been having irritating — if not debilitating — experiences with their shiny new phones. Their issues reportedly include dropped calls when using 3G networks and weak or flaky 3G reception. Reports of the cause are wide-ranging and rife with speculation, if not outright rumor. Apple, for its part, isn’t talking to anyone, it seems.