I learned, when I want to draw a circle in the yz-plane, I have first to type the key “arrow right”. Then draw the circle.
BUT my arrow-keys have no influence. I get always a circle in the xy-plane.
Can I activate the arrow-keys somewhere?
Or do you know, why these keys are inactive?
Your profile says you are using SketchUp 8. If that is correct, the feature you are referring to hadn’t been added yet in that version.
Thank you for your fast and perfect help!
Now it works! 
So you mean that you aren’t using SketchUp 8? Please correct your forum profile.
I had an old local version 8 of SU.
Now I have changed to SU free on the web.
Now, the arrows work fine.
How can I edit my profile?
Thanks!
This should take you to your profile page: