I think you`ve changed the URL rewrite settings without renaming <dokuwiki>/htaccess.dist to <dokuwiki>/.htaccess. You`ll also need to uncomment the rewrite rules in this file. See http://wiki.splitbrain.org/wiki:rewrite
for more details.
To revert your changes to the configuration you can also edit <dokuwiki>/conf/local.php with an utf-8 aware text editor and remove your settings.