Hi, I just noticed recently that my iPhone 3G was making a high pitched buzzing noise. It doesn't do it all the time, changing the screen brightness lower is when it happens. It is a very annoying noise - but it is the kind of noise only some people can hear. I am reluctant to take it back to Apple as this is the 3rd one they have replaced and I am worried about getting another with more problems. The first one had signal issues and was dropping calls, the 2nd had a screen problem where it would flicker with lines then go completely white and had light leak, the 3rd didn't even make it out of the car park as there was a huge gap between the screen and surround (with light leak). The 'genius' did say that they would escalate it if I had to bring it back again but I was given the one I have now. It also has some light leak but I was willing to live with it if the phone functioned fine... I am just worried about getting one with worse defects or one with a rubbish screen. Should I bother taking it back again?