No HD On Demand?

I have no HD options in the On Demand program guide.  Until two days ago, I had the choice of picking HD or non-HD versions of most movies and TV shows.  For example, for Game of Thrones I could pick "S1:E1" or "SI:E1 HD", but now all of the HD options are gone.  All On Demand shows and movies are standard definition only, and appear in letterbox.  Nothing else is affected: only On Demand is missing HD.

Also, the On Demand channel guide video in the upper-left corner that normally shows Camille Ford with previews of movies and shows is just blank now.  There's no video playing at all.

I called tech support yesterday about this but still have no resolution.  I reset my two boxes a couple times myself, and the support techs also reset the boxes remotely with no luck.  The tier 2 tech support guy also reloaded the channel lineup for my boxes but that didn't fix the problem either.  He did say he was able to replicate my problem, but if that's the case I would have expected to see some kind of resolution or notice of an outage: nothing, so far.