Chou has been inexplicably shutting down more-or-less every morning around 6:30; I assumed it was overheating or something. Then I plugged rutabaga in to the same UPS and it started doing the same thing [note: This UPS has threatened failure by showing a red "replace battery" icon on it's diagnostic panel occasionally, but it stopped doing it.]. Exhaustive research ensued. Found interesting hints on ubuntuforums.org about UPS snakiness. I have replaced the battery, though. If chou doesn't shut down for the rest of the week I'll call the replacement a fix.