Flags for the menus are separate from flags for the actual film. For example, one of the sets of Marx Brothers films I owned on DVD had the menus improperly flagged as widescreen non-anamorphic. My Panasonic RP-91 would auto zoom the menu so that I could not see all of it. Once the feature film...
I used to own a Panasonic DVD player (I think the model was RP-91) that would auto zoom and scale a non-anamorphic widescreen DVD on a 16x9 display if the disc was properly flagged. I removed the player from my system when the number of non-anamorphic titles in my collection dwindled -- I think...