I'm using the default xslt template for navigation, everything was working fine until I tried to change the default url for a menu item. Then I deleted the Umbraco Url Name field, but the item keeps showing up twice on my web site. Even though it only shows up once in the backoffice. I unpublished it, and it only showed up once, when I publish it, it shows up twice. Any ideas why this is happening? Im using 4.5.2.