Backing up the SuSE 10.0 DVD

I have a DVD writer (ATAPI DVD+RW) 4x4x12 and I'm trying to back up the SuSE 10.0 distribution DVD using K3B. I'm using the drive both for input and output (I assume an image is created in between). But K3B gives me the message "The writer does not support writing Double Layer DVD" as soon as it attempts the copy. What should I do to create the backup? Paul