I was watching both the DVD and Blu-Ray at the same time for all three episodes and the problem was at the same amount for all three episodes.
By problem, you mean the cropping was the same amount on all three? Hmm. That certainly runs directly counter to what I'm
seeing. Are you viewing them both on displays that have a 1:1 mode -- that is, no overscan? I understand if you mean that while watching one or the other you don't see a huge difference (because there isn't)... but unless you're stopping both at the same moment and examining them closely or taking screengrabs, how can you be sure?
Of the three, "Sins" definitely has the re-framing issue. Again, what I'm seeing is that all the non-VFX shots are showing about 85% of what the DVD shows. "Encounter at Farpoint" and "The Inner Light" generally give us a bit more, around 100-102% or so.
Hopefully when TrekCore gets around to doing full galleries of "Sins" and "Inner Light" we can all check for certain... but you can compare "Farpoint" right now if you haven't already: