By the way, for the records: I have solved this problem by setting the “extra” value in the primary key on the concerning database table to auto_increment. 🙂
*kick*
Is this problem very common?
Ah, thanks for your reply, but I already found where it should be. In wordpress_directory>wp-content>themes>theme_of_your_choise>index.php
I figured it out, so thanks for all the help!
