Ah ha! Same thing happened to me (twice) several months ago. I dismissed it and figured it was just my insanity because no one else had ever mentioned it happening to them. Good to know I'm not insane (yet).
It's obviously a bug. As soon as I did my "pit" and reset the service interval, every thing has been back to normal.
It's obviously a bug. As soon as I did my "pit" and reset the service interval, every thing has been back to normal.