I am running into this screen dimming issue when I am talking on my iPhone 3G. When I place the phone to my ear the screen does not dim all the time... actually it rarely does. Further, when the phone call is over, the screen does go dim and I am unable to turn it back on. Clicking on home button or on/off button does nothing. Sometimes waiting 10-15 seconds allows me to get back to the home screen. Other times a forced reboot is required. Is anyone else running into this?