Still getting cookie error messages, even after upgrade to 2.3.1. WordPress is in sub-folder so the WordPress address (URL) is different than Blog address (URL).
ERROR: WordPress requires Cookies but your browser does not support them or they are blocked.
ERROR: The username field is empty.
ERROR: The password field is empty.
Also get this after logging out:
ERROR: The username field is empty.
ERROR: The password field is empty.
Successfully logged you out.
Apache version 1.3.37 (Unix)
PHP version 4.4.7
MySQL version 4.1.22-standard
Also see http://wordpress.org/support/topic/144079 for a related report.