I just noticed that SD channels are filling my HD screen. How can I get these back to the "Normal" setting? Cycling through stretch, partial zoom, zoom and grey bar does nothing with the remote. This is on a ViP722 DVR, software L812. HDTV Setup is 720p with 16x9 aspect ratio, unchanged for years. I changed batteries on the remote a couple of weeks ago and lots of buttons got hit in the process, but no obvious setting on this side is amiss. How can I get SD back to SD? People look fat.