Help with new 2500a

I just got a second 2500 recorder for my other machine. Anyways, the new one makes dark rings on the disc for about the first 20% of the recording.
My other recorder doesn’t leave rings at all, even in this machine. The buffer is staying at 96 - 98 %. I’ve tryed Riteks, Legacy’s and CMC discs. The recordings varify ok but these dark rings worry me. Is this recorder flakey ??? Thanks… :confused: :confused: :confused:

Differently shaded rings are normal and will appear when the burner shifts from one burn speed to another. 4X–>6X–>8X
Run some Nero DVD Speed transfer rate tests and Scan Disc scans to test out your ‘shaded’ discs.

I have the Nero registry key set to show real time recording speed and it was going from 4x to 4.1x throughout the whole disc. When I tryed my other recorder it also fluctuated but theirs no rings on the disc nor any of the past discs recorded on the older (2 weeks) drive. My Sony 510 doesn’t leave rings either. I’m stumped. I don’t know whether to send it back or not…