Hey, I figured it out! Something about the Wysiwyg for WordPress plugin from mudbomb.com (http://mudbomb.com/archives/2005/02/02/wysiwyg-plugin-for-wordpress/), which I installed at the same time as the upgrade, was interfering with the login. I deactivated it and now everything’s fine. Thanks for your help!
Hmmm — clearing cookies got me to the login page, but then the page hung on me when I entered my username and password and hit “login.” This has happened both at home and at work, too, on Windows XP and Windows 2000.
