I have a system consisting of an HR-44, HR-24 and three H-25's on a SWM 16 switch. The last few days I have had pixelation and blocking with sound drop out on most channels for a few seconds at a time. This happens on all of my receivers and all channels EXCEPT my local channels out of Paducah KY. I did a system test with no problems noted and a signal test. All of my signal levels are above 90 with most in the upper 90's except on the (s) sats which is normal.. I rebooted everything and unplugged the power inserter. Nothing has helped so far. What would cause this problem on most channels except local channels with good signal levels? The pixelation is not continuous and has a good picture after a few seconds but starts again after a few seconds.