Regarding the H42L's riplock, see the recent review posted at ExtremeMhz.com:
Particularly read the section on ripping DVD Video discs, especially OTP DL:
"It was with the OTP discs that I encountered some issues. Even with the firmware loaded, this drive failed to provide higher read speeds on a majority of the discs. I ended up testing about 10-12 different OTP movies and only about six were able to rip faster. After troubleshooting a bit, I could not find the cause. After taking a look at the disc info on each, there was no clear pattern or reason I could come up with as to why it had no affect on the media[...]
In the end though, I was still very disappointed with the riplock on this drive and the fact that the modded firmware did not seem to have an affect on a majority of OTP discs. This is important to note for many because chances are, almost all your movie collection will be in this format."
As he also applied the MediaCodeSpeedEdit riplock fix, this likely explains why we're seeing inconsistent rip results (sometimes only 2-4X, sometimes higher).