A relative's iPhone 2G has a problem with the screen - the top part of the screen (basically, the top row of icons) does not respond to touch. There's no visible damage to the iPhone, and the screen itself works fine (in terms of displaying). I've already restored it to the factory default, and it didn't help. Any ideas what might cause this? Before I take it apart, is it possible that something has come loose inside to cause this? I can't imagine that there are separate ribbons for different sections of the screen, but you never know.