Yesterday my navigation screen had lines at the top and bottom, but no navigation map, it then went out after I pushed the map button. The audio bar comes up when you turn the radio on but has traff, flashing at the top, it then times out and the screen is blank again. My question, is there a reboot to the navigation system other then turning the ignition off & on, or do I have bigger problems with the unit? I have had the dvd bypass on for quite some time now and it never caused a problem. Thanks.