Any updates to this issue? I just started having the same problem with my DVR.
It also affects On Demand prpgrams. I can no longer play On Demand programs by selecting OK (nothing happens). If I select "Options" I can play a program in its default mode. For example, on Showtime I can play the SD version of a program, but I cannot select the HD version, as I could before. This is frustrating. Can anyone suggest a cause or solution? My STB is fairly new, sent to us about 3 months ago and was working fine until 2 weeks ago.