I have a Pioneer 107. I have noticed that I get a single ring mark when burning at 4x (but not at 2x). The mark is always in the same place (half way across disc at ~1GB mark) and with all types of discs used. I think that this may be where the write speed changes from 2x to 4x...but Pioneer are unable to shed light on this. All burns are perfect with good Nero CD/DVD speed graphs. Any thoughts on this! I also have a Plextor PX-708A on another PC that also creates a ring mark but at a much earl;ier position (very close to the centre, at about 300MB). Is it normal for DVD writers to produce such marks, particularly when changing write speed?
These are merely changs of speed in the laser. Very noticeable on the 8x burning when it shifts from 6x up to 8x. Nothing to worry about...