In my laptop, I have a NEC ND-6100A flashed to a NEC ND-6500A to get dual format capability. This burner has 8x max speed on DVD+/-R media. When I try to burn a DVD+R disc, the max speed only goes to 6x. I have tried 3 different brands and none of them seem to go at 8x when my burner is rated for 8x. What is going on here? Should I just keep trying to find a brand that works at 8x or is it the burner?