Just in case the Extension Routes module is still the issue on the 1st system: You have to go to Admin/Module-Admin and check if the Extension Routes module is activated. If yes, check the settings…
You are so right, did not see that! That helps!
Ok that did it for me!
It were two different problems with same symptom.
I double checked the first system and there is a CallerID in Dial Patterns
I double checked the second system and there was one extra 0 in forwarding number (asking myself why it worked before but ok).
I mixed it up … this was very confusing … sorry guys.
You both help me very well! Thanks a lot.
So guys thanks 1000xtimes 
Bye