i just got a 2005 magnum with the 6-disk cd and navigation from factory, first off i can't scroll down in the navigation menu at all, then i popped the cover off to where the navigation disk is and pressed the eject button, a chime sounded and it said navigation message on the screen, and now all it says on the screen is "insert DVD-rom"...the navigation was working fine when i got the car, i just couldn't scroll through the menu, guessing its the zoom button? but the main thing i need help with is to get it back to where i see the navigation screen, what does it mean by "insert DVD-rom? is there a way to reset it? thanks