I suffered that same problem. Went back to the store and the rep shows me that I kept touching the screen.
The screen is infrared touch sensitive, so it assumed I was still holding it to my ear.
Im still having problems.
Has your husband tried using your phone? When my GF kids use my phone, they have no problems.
I agree... If the problem is consistent. I would take it back.
But The problem seems like it's only me, so for now, I have to learn how to hold the phone a different way.
I never had any problems with my Blackberry's Non-Touch screen.
I'm getting too old for this new tech stuff.
I can't type using the touch screen either, because my paws are too big.
So have to either use the keyboard or the voice command.
Do you have a screen proector that covers the proximity sensors at the top left of the screen? Even if the screen protector is crystal clear it will interfer with the screen turning back on when you remove it from your face. Correct screen protectors will have a cutout for the sensors.