Radio Station Issues. Any thoughts?

Went into work today listening to Sat Radio clear as a bell. Went out to the parking garage, entered my car, started it up, and drove home. All of my Sirius stations, FM, and AM stations all sound like a static AM station the whole ride home. I plugged in my iPod, and everything sounds fine. I've had no issues at all and this is completely out of nowhere.

Has this happened to any of you?

I'm planning on letting the car "shut down" all the way some minutes and then I'll go restart it and see if that solves it.

Well, as a followup, everything is fine. I let the car sit for 20-30 minutes. I think when I started at work, the "hard drive" didn't boot up the right way and the radio just came on without booting up correctly. When I restarted it the second time, I got the "BMW" screen that comes up when you start the car, and all of the various radio varieties work... whew!!