Encore has a lot of SD on the HD channel but so far all have lacked the (HD) marking.
I have recorded and noted the following 4x3 movies on "HD" channels--
Max: Sunset Blvd., Thank You for Smoking
Encor: Aliens, Die Hard, Rain Man, Shut Up & Sing, The Last Temptation of Christ
DisE: Monsters
TDis: Aladdin
HBO: Snake Pit
HDNet Movies: Duel
Bravo: Say Anything, The French Connection (to be fixed on Sunday's 5-max)
Sho: Big Nothing
?lost: Paths of Glory, Spartacus (most times)
Classics (or as noted Duel) are understandable as they went to the theater (or TV) that way but more modern are just laziness especially Encore and Bravo. In fact, some pre-1930 movies are 1:1 aspect.
My second thought is that had I been more careful and recorded them in SD they would have been half the size for the same quality because they were just up-converted.
-Ken