Jonesy,
Sunspots do not interrupt satellite signals. Mass Solar ejections (eruptions of huge amounts of Charged plasma) can cause disturbances to the Earths Magnetic field, which can cause satellite problems, and Electrical grid interruptions.
A Huge Mass Solar ejection could take down the entire Electrical grid.
Clouds and Rain can scatter Microwave signals this is what causes 99 percent of signal loss.
Solar Conjunctions will cause the loss of satellite signals and these occur in the Spring and Fall every year when the suns apparent elevation in the sky crosses the path between your Dish and the satellite in space. The suns radiation obliterates the much weaker satellite signal for roughly 2-3 minutes per conjunction. This affects every receiving Dish on the Earth every spring and fall, whether you are program originator, a cable company harvesting that signal, or a home satellite user.
John