Ok, great. That's what I thought.
So, in DVD Player there are settings for how it reacts to the disk and how the movie is saved on the disk.
So, if you go into DVD Player and then go to the DVD Player menu and choose Preferences, you will see this:
This window shows the Full Screen settings preference. The third down under Displays tells whether to keep the video size as you enter full screen or leave it at the size determined by the Movie itself.
Now, click on HD icon and you'll see this:
Standard definition is defined here and it shold be set to Actual video size.
If set to Disk Default, it may try to show as a full screen movie but may be actually a widescreen movie. So it gets stretched, or blown up if it is supposed to be smaller, etc...
So, play with those settings and also try half size instead of full screen because that screen is big and these movies may not size properly so you need to change some prefs and try some different settings to get the pictures right.
And, some disk are different than others. so each movie may look better or worse.