Often when I choose a channel by typing in numbers on the remote ("2" "0" "5", for instance) the receiver immediately gives me the "No signal" error page that shows up when there's, say, a big storm in the area. Hitting the up or down button and then switching back brings up the channel fine. I started to notice this a week or so ago. It doesn't happen every time (a few times a day) and I've seen it on a few channels. Is something in the receiver starting to die or maybe some equipment up on the roof? I'll call it into dish but I'd also like to have an idea what is broken.