Got it, checked the box and my problem was, that i tried to be TOO exact XD.
Cause the Box changes during ducking, i had do specify the box manualla(to have more controll). Well, for the duck box, i did everything correct. X and Y axis had the same size. But for the stand box i did it wrong. I used a lower X numbers.

You should see it in the pics below:
[WRONG BOX]


[CORRECTED BOX]



I'll upload a fixed version later. But as far as i can see, thats all i had to change. nOw everything seems to work fine.

Greets
Rackscha