About a year ago I obtained the series Blake's 7 on Region 2 DVDs. I did so because they'd never released it in Region 1. I was able to convert them for use on my Mac mini DVR system without any hassle.
I recently acquired another set of Region 2 DVDs, The Thin Blue Line (the complete series for $13 - and that included shipping from England!)
This time VLC and Handbrake wouldn't read the DVD. I was able to resolve the problem by launching the Mac DVD PLayer and changing the drive's Region Code when prompted.
Now in Region 2
I suspect, but don't know for sure, that Blake's 7 DVDs I picked up last year were not encrypted. I'm going to pick up an external DVD drive for the mini and leave my Mac Book Pro's DVD drive set for Region 2.