On my iPhone 4, when I am done with a call and want to hit the "End Call" button, I have the phone away from my ear, and hit the "End Call" button...the screen goes black and flickers for several seconds before it lets me end my call. I think this is a proximity sensor issue, but was wondering if anybody else is having this similar situation when wanting to "End Call". Again, the screen kind of goes on and off several times after I take the phone away from my ear and try hitting the button, it doesn't end the call the first time I press the button, I have to press "End Call" several times to get it to hang up. This is really annoying.