Bought a Pioneer DVR-A07XLA last week. The store threw in a bonus 5-pack of TDK DVD-R 4x disks. However on my burner they would only write at 2x. One of the guys at the store has the same burner, same firmware, but he insists his will burn these disks at 4x using Nero6 as I do. After flashing the newest firmware, still the same result. Also tried a different batch of disks but still the same. Other cheaper DVD-R’s have burnt at 4x. Is there any reason for this occuring, providing the guy at the shop is not wrong?