DirecTV receivers can't generate a HD and SD guide simultaneously. You're seeing the error that's produced when the box is asked to do that.
My family back home upgraded their DirecTV packages to HD and my Slingbox ProHD is now connected to a DirecTV Genie Mini C41-700. I now have a problem and this is that when I try to change channels I get a message saying that my box or cable are not HD and I need to hold ESC on my remote to make this notice disappear. I can also no longer open the "list" or "guide" from my remote.
Is this due to the missing HDMI input/output on my Slingbox Pro HD ? I went ahead and ordered a Slingbox 500 hoping this will resolve this problem. Does anyone have any insight on this?