Dear Colin, Ian and Luis,
First of all sorry for my late reply. I was a few days out!
And sorry for my ambiguous formulation of my problem, using "deviation" a complete wrong way. As a sailor i had to know better!
Many thanks for Colin's solution.
I disabled my latest scenery add-ons ( EGBB; LOWW Vienna; abudhabi; and The Alex Fraser) and the problem was solved. Everthing works correctly.
I will find out tomorrow which one of the 4 scenery add-ons is the guilty one!
Kindest regards and thanks again for your highly estimated help!!!
Carl