Maxell's not burning at 8x on 708A

I have some 4x Maxell DVD+R’s and they are Ricoh’s. Why do some of them burn at 8x and some of them don’t? I am using firmware version 1.04 and am using Nero to burn. Usually the discs will start at 6x and then go to 8x and then drop down again, but lately I have been burning only at 4x constant…and have no idea why.

Although your media can work at 8x there is no guarantee that the discs actually work at this speed. During the recording process the drive monitors the write quality of the discs and if that’s not good enough the write speed is decreased. Although you’re using discs from the same batch, this doesn’t mean that every disc will be burned at 8x. Nothing you can do about this really.

I was assuming that’s what was going on, but I just wanted a confirmation from someone who knows what they are talking about. Thanks Gamefreak for the reply.