In season 6, episode 2, "I on Sports," the news anchor's name was Joanne. Toward the end of the episode, however, in the final commentary before Sam is fired, when the puppet "Little Sam" tosses it back to the anchor, it sounds to me as if Sam says "Diane." If true, an obvious slip after 5 years of saying Diane.

I noticed this for the 1st time very recently when re-watching the episode on DVD. Does anyone else hear what I heard?

I heard that myself.