This just began happening today when I turned on the NAV and the door to the DVD tray was open. My NAV system is telling me I'm on roads and in places that I'm not. When I turn off the car and restart later, it is correct for a while, but once on the interstate it won't recognize that I've made an exit. When I pulled in my driveway the NAV system thought I was in a field nearly 10 miles from my house. Is it malfunctioning or does it need a CTRL-ALT-DEL style reboot?