Okay, the subject does not cover my entire problem. :)
I have been busy trying to get Ultimate Tag Warrior going and I stumbled upon something odd-ish.
At some point during the installation you have to make a page that uses the template of UTW. I can do that, being a WordPress veteran. ;)
However! WP fails to find the page I have created if I use the url it is supposed to use with the permalink option I use: %postname% which I think should be: http://strikdiploma.nl/tags. It does work when using the WP default permalinks: http://strikdiploma.nl/?page_id=366.
How can I get my WP installation set up to be able to use pages normally with a funky %postname% permalink setting? :)