Something must have changed somewhere. I ripped out the DAV Akonadi connector, and re-added my address books and calendars using the _exact_ DAV URL. I recall it used to find them automatically when I put in the base URL and hit "Fetch." Now Akonadi needs its hand held through the process. So let's see how long it works until it breaks again... Still willing to support an Akonadi-less KDE PIM suite.