Okay, login screen actually came back about 8:00 last night, cleared the cache, and the site looked fine for the rest of the evening. But, now today it's doing the wacky formatting thing. The login screen is still there, thankfully, but the islands are still clustered at the top with the threads at the far bottom.
Rick, could making sure the templates directory is cleared out (except for index.html) help the formatting issue, or was that just a suggestion for the AWOL login screen?