I have a Nuvi 775t with Cyclops subscription. In the proximity settings the choice is 'once' or 'continuous'. I want to hear a warning once but the annoying beeps continue even 1 MPH over the current limit. In the UK we have a lee-way of 10% + 2 MPH. Why can I not turn off this continuous warning but still have one beep. If I turn off both sort of alerts will I not get any warning?