Randomness #2

I don't understand why my XM radio in the car sometimes changes stations. Like, the Elvis channel and Backspin, classic hip-hop, changed places today. Seriously. Backspin was my programmed channel 5 and Elvis was 6, and now Elvis is 5 and Backspin is 6. Plus, somehow channel 10 was BPM (dancey stuff) and changed into LOVE. How does that happen? Does my radio just decide it wants to hear certain stuff? Does it think Elvis is more important than old skool rap? Creepy.