I did what Gerrit asked me to do and made a photo of this.
The calibrator is totaly out of doubt with a counter result of my HP counter at 500,007kHz.
The problem is the non congruet alignement of the DOT marker with the DC-Marker when the DOT frequency is 000kHz.
If some one could tell me how to alugne that dot Marker to the DC-Marker, it would be the solution.