The hook of the bar are not just mounted on the model ordered, but in some cases slightly twisted to the left. The cross braces are not just. Both seem to be producing errors, because you can not change manually.
We have retained the bar anyway, because it is practical and it does not depend forward to the optics.
Updated on 31.8.2014: We even bought a second bar because it is so beautiful and practical things to the round hooks are in good hands.