DVD-ROM Backup problem

I am a new user to CloneCD. I wished to backup a DVD-ROM from a car navigation system. After successfully installing CloneCD on my machine, I carried out the copy operation, seemingly without a problem. The copy was onto a dual layer DVD+RW. I used the “Hide CD-R media” option (ticked) in the tray icon. However, when I put the disc into the car navigation system, it said that the disc was not a navigation DVD. The only thing I can think of is that the navigation system can tell that the inserted disc is recordable DVD media and not a DVD-ROM disc. Does anyone know if there is a way around this, or perhaps there was something else wrong in the copy process (settings)?? Any suggestions would be much appreciated.

I succesfully backed up a Zenrin Nissan/Infinti Navigation System Map Data DvD (v6.2) using DvD Decrypter (v3.540).

The key is to use a drive (I used a Plextor PX-716A) that supports changing the Book Type for DvD+R DL media to DvD-ROM so that the navigation system will see the burned disc as a DvD-ROM (as is the original disc) and not a burned DvD+R DL disc.

DvD Decrypter allows you to change the Book Type for DvD+R and DvD+R DL media to DvD-ROM on drives that support the changing of media book type (bitsetting).-

Tools==>Drive==>Change Book Type

After changing the Book Type for the media, first created an image file (.iso) of the Map DvD with DvD Decrypter using the ISO read mode. Then burn the image file onto a DvD+R DL disc using the ISO write mode.