Okay, I finally got it to work!!!
What happend is this: I got several error messages from the licence control when running Cubase 6 lately.
But Cubase was working flawlessly and I had installed the latest eLicenser Control Center, before I installed Wavelab the first time.
But… Than it hit me, I had some problems with the boot drive, so I re-installed an image from a week or 2 ago.
Installed Wavelab again, but forgot about the newer eLicenser Control Center… 
So, nothing special on my system. 