Nothing wrong with that, but my point is it's not as simple as those "lazy/incompetent Guppy pilots" or "bad 737 systems" that have become staples of forum speak. The NG AC works great on the APU, but for a variety of reasons, ranging from lack of communication to being "clue minus" in the pointy end, sometimes the back end of the plane gets hot. Happens in all of the fleets.