Have you checked to make sure that the dish is properly bonded to Earth ground, and also the static block where the line enters the home is properly bonded to Earthing ground. This whole incident can be caused by a poorly grounded system to the Earthing ground. The same ground rod that your Meter or Main Panel is bonded to, should also be the same point that your dish should be bonded to.
I try to always use the ground rod for any telcommunications, catv or satellite coming into a structure, since it will also be bonded to the electrical feed coming into the home. Now of course, if you have one of the older Single phase electrical systems, that the ground is used as return path, then you can end up with poor Earthing bond for any communications systems, which in turn when you disconnect say hdmi, coax, Component or Composite line from receiver to a tv, you can cause problems.
See this a lot with computer systems, that when you disconnect the Ethernet line or monitor to the unit, it causes the system to reboot, because it looses the ground between the two.
And yes, a bad receiver can also be the cause of this, even if you have gone through and checked all system grounds, and they check out that they are in order, then the last thing to look at is the satellite receiver as a possible culprit.