Codeigniter Index Controller routing problem
The documentation actually states that a controller can't be named 'index' because it's a reserved word.
If you goal is to get pretty URL's you should leave the default controller as it was originally and leave the $config["index_page"] variable empty.
Then create this .htaccess file:
Options +FollowSymLinksRewriteEngine onRewriteCond %{REQUEST_FILENAME} !-fRewriteCond %{REQUEST_FILENAME} !-dRewriteRule ^(.*)$ /index.php/$1 [L,QSA]
That would make CI and you a happy couple...