Why did I suddenly lose satellite radio reception?

For months, I had great reception in my office building (in downtown Madison, WI), and also outside my building when I took walks with my Sirius Stiletto 100 using only the internal antenna. But starting last week, I lost all signal strength in the building, and outside it has become extremely choppy. But them I'm sitting here in my living room getting reception with the internal antenna. I live 10 miles from work, so there shouldn't be that much difference. In fact, if there's a ground signal repeater, I should get better reception downtown. The catch is that my subscription ends next week, and I don't want to renew if I can't get reception at work anymore. But then I don't want to be forced to cancel and be left wondering if it was just temporary. Any ideas?