I recently got my hands on a new Navi-DVD but the second disc for east coast and I live in northern CaliforNIA, and I was tempted to put it in my D1 and so I did. After it updated my system, it will not accept the 2005 Navi DVD Disk 1 anymore. It keeps giving me the " Please Enter Appropriate Disk" message when I put my old navi-dvd in. Anyway that I can downgrade to the old 2005 version so I can use my old navi dvd instead of paying for a new navi-dvd disk 1?
2005 GMC Yukon SL
Pioneer AVIC D1
Almanni 700W
Dual Electronics 2x 12"