If the original is already damaged you might not be able to make a disk to disk copy. You can try to copy the files off the DVD to your hard disk first and see which file is causing the problem. If the DVD is not totally broken, you may be able to use some sector copy tools to get if off the DVD. Once you have all files on your hard disk you should be able to write them back to DVD+DL media. Nero doesn't like the large KWI file on an ISO disk but some said UDF is sufficient and recognized by the RNS-E. And if you don't wanna go the route, maybe Navteq is will to send you a replacement if you return the broken DVD...