Windows 7: HandBrake

I had been using HandBrake without any problems, until last night, when one of my DVD drives started having a problem (damaging a DVD), so I switched drives and DVDs, then tried again. From that point on, when I select the source drive in HandBrake, regardless of which of the 3 drives used, it never gets past detecting the first title of the DVD. I reinstalled HandBrake twice, with no improvement.

That was in XP, so I just tried it again in Windows 7, but the problem remained, so I uninstalled all 3 drives in the Device Manager and rebooted, and though the Device Manager says that they have no problem, HandBrake still doesn't work.

While HandBrake is attempting to detect a title, the activity light on the optical drive selected, remains either steadily lit, or lit with a very slight flicker. This would seem to indicate some kind of hardware problem, yet both DVDFab and WinX DVD Ripper work normally. How do I determine what the problem is?

EDIT: The DVDs that I had been using were all from the same boxed set, but I just tried another DVD unrelated, and it started working normally, so I guess that the problem was with that entire boxed set, rather than HandBrake. That is curious, because the other 2 encoders have no problem with them. I know that HandBrake is not capable of working with a copy protected DVD, but usually, it would pop a warning message, if it had that problem. Well, the short of the story is that I guess that there is nothing that can be done about this, so you can ignore the question.