I just found this out and it makes the phone useless. When you make a call and hold the phone to your ear tbe screen goes off. Which is fine, thats what it is supposed to do. My problem is that when I move the phone from my ear the screen becomes unresponsive. It doesnt turn back on and pushing the home/sleep buttons do nothing. When the call ends I have to lock then unlock my phone to get the screen back. I was stuck in an automated phone call and could not use the screen to get the keypad and I could not end the call. I had to hold the home and sleep buttons to do a hard reboot.
wow i wish i read this earlier. I called apple support and they just sent me a new iphone replacement today and its been shipped lol. Oh well lol!! Thanks for the info