Hasselblad Phocus - wrong output size??

[usm]

When I am setting the output size in focus to i.e. 1668 width and let the hight blank, every image should be 1668 pixel wide.
But the image with Keystone correction comes out with 1806 pixel.

What I am doing wrong?

 

[bab]

Crop outside image

 

[usm]

Crop outside image

Is not checked

 

[usm]

When I just use a horicontal or vertical keystone correction the output size is correct. It doesn't matter if I set pixel or cm...