Go Live 1005 finds GPS signal and tracks position perfectly. When a destination is entered it calculates the route indicating distance and time, however when you confirm ('done' button) it locks up and the screen alternates from blank to the start up screen. Eventually, anything from 5 to 45 mins, the screen indicates no valid GPS signal. This only stared to happen following the April GPS update. I've tried resetting several times and the same thing always happens. Has anyone got any ideas??