I have a Pioneer 520, which I am mostly pretty happy with. I have been using Ritek G05 disks to copy from the HDD to DVD-R at 8x quite happily. As I was running a little low I bought some of the the new Datawrite 'Titanium' Silver 8x disks, which I believe use a CMC dye. However, these disks will only write at 4x. Is this because it is a new disk that the firmware doesn't recognise?