Fixed a problem that prevented people from registering for events. Among other things.
web10.dk have finally answered my support-request. They have changed the configuration of the host. Without telling their customers in advance.
Unfortunately the change in incompatible with our site and with normal recommendations from the World Wide Web Consortium. And the only way to fix it is to make changes to the code behind the pages.
I'll be investigating if we can change to a different more customer friendly provider.