My wife has an Evo Shift. Her phone's volume up button would cycle through sound/vibrate/silent modes. We found her phone in vibrate/silent modes from time to time. So we traced down to the volume up button. My Evo 4G does not do that. Is there a configuration in the Evo Shift that can disable such function? In other words, we don't want the volume up button cycle through these modes. Thanks.