Broken Links in Events+

I have set the Events base permalink to be "begivenheder", and links like this work just fine:

http://mysite.dk/begivenheder/2013/01/very-eventy-event/

But I receive a 404 Error (even after re-writing permalinks) here:
http://mysite.dk/edit-event?event_id=5054

This happens to all edit and add instances.