Ok. It turns out after much searching through forum posts, that the company that hosts my site had done some things on their end which affected all sorts of admin functionality.
They’ve rebooted their web server and now it works again. Big sigh of relief.
Oops. Sorry. I just put wp-admin.css back but unlike you, I don’t see the login page on FF. Bizarre.
I’m running OS X 10.4.9.
