I am trying to reset the clock using the setup button on my Navi. Once I press the setup button I get a screen that has a "Others" field that should take me to the "clock" option. However the "Others" button seems to locked for some reason (its backgound is grey rather than white). When I press the "Others" button I keep hearing beeps - does not let me move to the next screen. Can someone help me with this problem ?