It's possible that it may have happened in isolated examples, but it's certainly not a common problem.

I remember reading old Video Watchdog articles where they described something like this happening with some laserdisc releases. Something about blowing up the picture within the letterboxing (making the picture easier to see back in the day before people had large, widescreen TVs). I think they called it "zoomboxing" and used the LD of JURASSIC PARK as an example (and it looked close to what is shown in the JP pics in the post above). Is it possible that some of these fiddled-with LD transfers migrated to some DVDs? (especially earlier non-anamorphic releases?). I have no idea if this is the case, I'm just throwing this out there. :)