Just registered. I'm new to the forums, but not to the iPhone. I've had iPhones since the 2G, and currently have the 4s. I have to say, I'm a little disappointed with it so far. The only iPhone I haven't had so far is the 4, but this phone is by far, the most problematic. I'm on my 3rd one as its been switched out for many different reasons, and now I have an on going issue that exists since I first got this 4s (all three 4s phones experience this). I'm not able to hang up my phone sometimes, and I have to press the power button to do it. It's been happening since I got the first 4s, and with every one after. I've already tried turning off the phone; doing a hard reset; restoring from iTunes; doing a firmware restore and setting up as new, and none of them resolve this. Does anyone know a solution?