Hi everyday I'm having my iPhone 4 with iOS5 crashed during a call, it work normally for a few seconds but freezes all the sudden. I have to press the power button for some time and then hold the home button for it to restart Even after the restart it doesn't work properly, like starts call with speaker activated and if I turn it off crashes immediately. Sometimes it seems to work properly. What can I do? Next phone will be Nokia.... those guys have been doing them since ever.