I would think that at least ONE of you out there has XM ? Have you noticed this phenomenon when using only your XM presets?
My radio behaves the same way. It only scrolls the name and title in the situations you described or when a new song starts.I know you can cycle it manually by pressing the Title button but I also found if you find a channel using the seek button or selector knob that when a song ends and a new one comes on it will scroll the artist then song title for a few seconds and then back to artist. It won't do it if you control stations through presets alone -- See Option 1 vs. Option 2 in my first post .. (at least that's been my experience).
wkndrdr are you able to try Option 1 vs Option 2 and let me know what you find?