Spotty signal, certain channels

Can you define "spotty"? Or better yet, take a picture?

Also, when your on those channels, and you bring up the guide, is the guide spotty too?

It's spotty as in the signal is going in and out, causing loss of audio for a second or so and pixellation. A signal error message comes up, but it appears and disappears so quickly I can't read it. The guide works fine. I've got Comedy Central in now and cannot even understand the program because it is happening so often. It has been happening on these two channels ever since we went digital, though the other channels work fine. Thank you for your help.

Spotty signal certain channels said:
loss of audio for a second or so and pixellation

You hit the nail on the head with pixelation. The message may be "Temporary Off Air...". Probably means the signal for those channels is problematic. It might even been happening before, but you didn't notice it when analog, since you don't need as much signal for analog, and when analog signal gets weak, the picture is just a little fuzzy. 

Do you have any other boxes in your house? If so, does the channel pixelate on those channels too?

Finally, when was the last time you had a technician out to check signal levels in your home, specifically the outlet the box is on? Do you know how the cable/coaxial is routed through your house? Any splitters you can replace or bypass?

Tecknowhelp said:
......but you didn't notice it when analog, since you don't need as much signal for analog, and when analog signal gets weak, the picture is just a little fuzzy.......

I find this interesting, but saying analog “don’t need as much signal” I presume you mean signal strength?

If correct that might mean after digital conversion some may experience problems they haven’t noticed before, requiring rewiring and such.