[Bog]

You have to do this part, from the wiki:

"Every time you add a new category to your site you need to update the mod rewrite rules for the category urls. Simply go back to the admin panel / category management page copy the new rewrite rule and paste it on top of the old one in your .htaccess file."

If you look at the category management page on the admin, it gives you the rewrite lines at the bottom.