Hi
If you are not using an inverter to charge your phone in your cab, and you are using a USB port similar to sync in the car. That is going to be why you're getting that message. I can't think of the technical terms to explain it, but basically your phone thinks it's being hooked to a computer, when you hook your phone to a computer it looks for certain drivers, to which your car's USB port does not have, thus generating that message.