If the problem is as you say then it would be impacting everyone unless you are being served by a faulty repeater in your area. But if no one else is having this problem via the sats then I think your diagnosis is wrong!
I'm in the boonies - about 25 miles south of Boston (MA). I get a zero terrestrial signal, so I guess that means I'm relying 100% on the satellite signal.
I'm currently getting great car reception and 2-3 solid bars in my home dock (both with my original, almost 3 year old antennas). Last Friday with the same receiver, docks and antennas, acquiring signal problems made Sirius unlistenable in both my car and house.
Unless moving a receiver from dock to dock (i.e. plugging and unplugging) produces variations, the only conclusion I can make is that satellite signals sometimes go away. Hey, that might just be the nature of satellite reception in some places.