We are using ldap for authentication. And we use the K2 User module to login. When the userlogin is correct and the user is not yet registered in Joomla the ldap plugin add the user to Joomla (name loginname, emailaddress and the default group "Registered").

This user then has no group in K2.
I want the user to be able to add a new article in a certain K2 category. How do I do this?
I can add a K2 usergroup and allow the users of that group to create items for a category. But then I have to manually add every user to the K2 group after their first login.

Please some advice on how to handle this problem.

I have the same issues :( , please help.