unfortunately, my 3g iphone is defective and i need to replace it. the sensor, i believe, is the problem. instead of turning off when you hold it to your ear during a call, it turns on and turns off when you pull it away. this makes it difficult for me on my end to hang up the phone if i want (because the screen is black and i cannot 'end call') and causes the speaker to activate because my face touches the screen. anyone else having a problem with this? or am i the only unlucky soul?