If one decides (for whatever reason) to run his mysql-server passwordless it's pretty hard to figure out why phpmyadmin doesn't work. Adding $cfg['Servers'][$i]['AllowNoPassword'] = FALSE; to the default config.inc.php would make discovering the option a lot easier.
Will try fix this with the next phpMyAdmin update.
This bug appears to have been reported against 'rawhide' during the Fedora 13 development cycle. Changing version to '13'. More information and reason for this action is here: http://fedoraproject.org/wiki/BugZappers/HouseKeeping
phpMyAdmin-3.3.3-1.fc12 has been submitted as an update for Fedora 12. http://admin.fedoraproject.org/updates/phpMyAdmin-3.3.3-1.fc12
phpMyAdmin-3.3.3-1.fc13 has been submitted as an update for Fedora 13. http://admin.fedoraproject.org/updates/phpMyAdmin-3.3.3-1.fc13
phpMyAdmin-3.3.3-1.fc13 has been pushed to the Fedora 13 stable repository. If problems still persist, please make note of it in this bug report.
phpMyAdmin-3.3.3-1.fc12 has been pushed to the Fedora 12 stable repository. If problems still persist, please make note of it in this bug report.