Cannot change the channels or pull up the guide without a message stating that my TV needs to be set to standard definition by holding the exit button. Can't even manually input the channel number. Only presets work. A/V and TV at home are all properly wired for HD. Never had this problem before.
There have been lots of people reporting this. It's nothing to do with Slingbox it is a DirecTV firmware update. Do a Forum search for other threads, and quite a few of them are in the "More Like This" just to the right of this message on your screen.