Hi, I have bought a dual layer dvd-r with 8,5 gb (isn't that a dvd9?) so I can make a backup of my laptop. But when I want to burn in my dvdburner on the laptop, NERO is only record 4,7 gb as a normal DVD? How do I tell it that I put a dvd with 8,5 gb space? -The DVD is: Verbatim, Dual Layer DVD-R, 8.5GB, 4x certified 215 min, Advanced AZO