Audio crackle on a new H21

[SatPilot]

My older H20 receiver was starting to pixelate (is that a word?) certain HD channels (ESPN, TNT, USA, TBS, Spike, etc.). So Directv sent me a new H21 to replace it for free.

Now every time I change a channel (except for the XM Radio channels where this does not happen) there is a loud audio "crackle" before the picture signal appears. This is very annoying.

Native resolution is off. I have a multiswitch downstairs (I have a 5lnb dish with an HR20 and HR21 downstairs and this H21 upstairs) but don't know the model number of the multiswitch.

All signal strengths are well above the high 80's except 103(a) which is in the high 70's.

Any ideas?

 

[charper1]

Is your DirecTV receiver connected directly to a TV with only 2-channel audio? Likely so.

Go into the DirecTV receiver's audio setup menu and TURN OFF dolby digital.

 

[SatPilot]

I forgot to mention in my original post that dolby digital is off.