Originally Posted by Hayesimus
why WOULD you hit the top button?
Beat me to it. Not to be a smart a** but there is no reason to do this. You will have no extra battery drain while you are on the phone. The screen dims when you are on a call.
To your original question though, I have no answer because I have never tried this. I would seem to me that it would hang up on the caller, but if you say it used to work I have no idea why it doesn't now.