You are right ken. This has been going on since they interduced the Ch 9000's.
What I have been doing while they are playing around with the Ch 9000's, till they get it right for those channels, which seems to be the thing going on.
I go to Video Setup & switch to 16.3 & that makes the SD stations open up to full screen for the SD version channels as to the same channels that are in the 9000's HD.
The picture opened up in SD 16.3 is not to bad. Not bad. Some IPTV boxes do it automatically, but some have to be turned over to 16.3 video manually.
As on PVR programs etc.