I think that did it. Not sure what was wrong, but after deleting and reuploading WP, it appears to be working again (although it’s asking to update the database). Thanks for the suggestions!
I did re-upload a clean version of the wp-admin folder, too.
I disabled the Fishpig extension in Magento, and got a 404 error on the admin login page. In fact, that put a 404 error on all pages. So, when I turned it back on, all of the live pages then worked again.
From the thread you referenced, the .htaccess file is set up correctly. Again, I didn’t change anything between it working last night, and not today. I also tried the added code suggestion for the fishpig_wordpress_helper_system, didn’t help.
I’ll look at the plugins/themes/core, let you know if I find anything.
