I am using Iphone 4. I believe it found the problem. I find that the grip on the device plays the bad signal reception. And not all are housed in the same boat. Some speakers stressed that the use of the device with the left hand problem. I already know that we must take the iPhone in the left hand , with respect to antenna completely obscured by the hand. But we also have sweaty palms , sweating enhancing conductivity . Please help.