Rumor of the Week

I'm reading another blog (Can't link to it; it's a secret... ON THE INTERNET.) and they rather casually mention that the reason for Memphis Mayor Willie Herenton's extended public absence last summer was that he was in rehab? Can anyone add to that? Any media people want to tell us it was widely known but they couldn't report it for one reason or another? Was it something else, equally unreported but much less salacious?