We have a 2011 Sorento EX with the factory DVD system. Yesterday, on a trip with our grandchildren the unit would not power up. We stopped at a Kia dealership in New Jersey and they were able to reboot the system to get it on. The service manager said this has happened on a few cars before and we should schedule a service visit at the dealership were we bought the car since the unit may need to be replaced . Anyone else experience the problem and what was the permanent fix?