Hi Michal,
I'm using RC 2.7.4.
I'll send you the file to look at. The issue is with the directions of the UVW offsets. I've attached an image to illustrate the point. The object Wall_Main has the "Apply Box Mapping" option checked, so I assume it has a box map, U, V and W applied to it. However, when you then edit the UVW XForm, as you can see in the attached diagram, the U value moves it in the front face X direction (as expected) the V value move the front in the Y direction, but the side in the X (local, or Z/W to the front face), and the W value seems to do nothing at all!
I hope the file, or the diagram can explain it.
Cheers,
Bill