Thanks for your reply!
In response to a message in that original thread:
"DVD-ROM drives do not respond to the read-speed commands from Kprobe, so they will always scan at full speed. This is especially bad for DVDR scanning."
For a liteon 166S this is not true. I time the scans and 4x reads at approximately half the speed as 8x, and so on. I havent tried every speed combination but the DVD-ROM does respond to different speed settings.
"DVD-ROM drives do not appear to report the same types of errors as C1-C2 and PI-PO as the burners do. We do not know what they are reporting, but there does not appear to be any predictable relashionship between what gets reported on a ROM drive and what gets reported on a burner. "
Hmm.. I wonder what is being reported. I have tested a lot of media using the 166s and firstly, the same disc, tested months apart under the same settings, gives approximately the same results. I mean they are really very very close. Secondly, discs that I know are bad and not very readable in other drives test worse, if I put smudges and other things on them they get worse. CMC and Princo 1x discs have poor results. Name brand MCC discs test well. Sometimes most discs on a spool test well but one on the bottom will have worse results so I know to test it in a standalone player or in Nero speed test. Conversely I've never had a problem with a disc that had a good Kprobe result. It certainly looks like the 166S is behaving just like a DVD-Writer in kprobe tests. If its not measuring the PI/PO errors, its certainly reporting something with a very strong correllation to it.