Many upconverting DVD players have a menu option asking how you want the signal displayed for non anamorphic DVD's. If your player has that option, that is how you can adjust the picture. The other option, if the DVD player allows it, is to turn the upconvert feature off when viewing a non-anamorphic DVD. Then the TV should allow the stretch modes to work.
If you can't figure out what features the DVD player has, post the model number and I'll take a look at the owner's manual online.


