I found this in the error log:
[Sat Feb 19 12:40:38 2005] [error] [client 66.249.65.234] File does not exist: /home/thewrite/public_html/404.shtml
[Sat Feb 19 12:40:38 2005] [error] [client 66.249.65.234] script not found or unable to stat: /home/thewrite/public_html/submit.php
This sent me looking into my WP files, where I couldn’t find the submit.php file. I’ll check the WP files that I downloaded for the upgrade to see if I inadvertantly skipped this file.