It also occurs when I installed everything on the server without importing / converting any data, so it has to be an issue with either the host, the software or a configuration mistake of mine.
The address to the board is
http://www.a-s-charmed.de/vbulletin/ , I supplied this address in the members area so it's the public installation.
As you can see, everything is set to its defaults, and there are still the errors...
Edit: The issue has been solved, thanks to Steve Machol again!
It was a strange cookie which caused those error messages and I was close to reverting back to the Ikonboard because of all this ...
Icheb