Wow, I'm surprised there's no post here by now. Anyway, all the HD offerings for EPIX OnDemand are completely removed. Don't know how or why. Maybe they're fixing THOR and CAPT AMERICA so that 33% of the picture that was missing will be restored?? (Ok, I know...not a chance that'll happen....but one can dream.)
Perhaps a temporary problem at your VHO. They show up on my boxes.
You might want to double-check. The title list for the OnDemand offerings are all there...but they are SD and not HD. (I'm in VHO 7, but I've also heard from people in VHO 5 and 8 and the same thing has happened to them)