Actually, my calls drop all the time. When I am on a phone call while holdin the phone at the top, very uncomfortable, I start to relaxe and my hand slides down to it natural holding position and before I know my hand is covering the antenna and I get the three beeps of frustration.
However, just yesterday I was in a different part of Chicago, and everything was just fine, so it's definitely location specific.
So why have you not exchanged your phone? Or have you. Also odd that in some areas its an issue, other not. I forget, does ATT use several frequencies? And if so, could it be frequency related? Just a thought.