i bought my N1 in oct 2004 it came with CNDV-40MT DVD's for the maps couple years after i upgraded the DVD's to CNDV-70MT and now my system's just horrible. I cant watch dvd while driving, seems like i cant even get the maps feature to work cuz everytime i put the 70MT DVD in the search address feature is grayed out, please help how do i go back to the old DVD's because when i put the old DVD now it says its not the right disk i even reset'd the unit still no luck.