Today, I was able to recreate the problem and that's why I've started this thread.
Today, I put the 722k in interactive mode to check on the weather. When I came out of it, all of my HD channels were locked in SD just like the other day. After fiddling around with it and confirming that my Mode switch didn't do anything, I went back to the interactive app. When I came out of it, the correct aspect ratio on all of my HD channels was back. It actually acted like a toggle switch of sorts.
Edited by Henry, 11 January 2012 - 12:29 PM.