Thanks for your reply Andydigital,
I tried to push the buttons all differend ways, but unfortunately it's not the solution for my problem.
I posted my problem on several forums, no one seems to be familiar with this problem.
I've send a mail to VRinsight tech.support, they are not responding or what so ever.
So I have this wondefull looking CDU and my fingers itch to program the CDU and fly :O
Hopefully it's just a matter of (short)time, and there will be someone who can help me out here.
Thanks again Andydigital!!