Dear Adel,
I have bought the IP4 in Sydney unlocked. From the very beginning I had the home button problem 8 out to 10 times when was pressed. As I posted, when I placed in off, the location services, the home button only failed 2 out to 10 times, so for me is a software problem. When I place on the location services the problem starts again. Also every week I blow some pressure air in the plug slot, cause somebody told that might be dust in any place. Since 4,2.1 software was installed, by the moment I had not the problem. I will cross fingers.
I am also agree that is not a precise software problem, is randomly in every IP4, other customer posted that the problem was the camera application. I am agree that some apps stuck the home button.
But if you have bought the IP4 in USA, must be returned to the place were bought it for exchange.
I have 2 friends that had exchanged twice the IP4 and still have the home button problem.
Believe it or not!!!!!!