On this particular DVD, I used 8x... :bigsmile: Over in the LiteOn forum, there's beta firmware available that allows that media to burn at 8x. Interesting thing is, I got a rather good quality score from Nero's CD/DVD Speed. It was 93 or 95, as I recall.
Personally, I don't buy the "slower is better" thinking. I won't automatically blame this issue on the burn speed I used (yet). If media is rated at speed "X", it had better burn reliably at that speed, IMO.
I'm suspecting the booktype myself. Remember, on this DVD, I had forgotten to reset the booktype to DVD-ROM after updating the firmware.