Yes i must press save (not just "V" ) to make settings active.
PS
I keep searching and found that this question needs ABAP programming see note http://scn.sap.com/thread/1685997 the point is that each order needs tcode IW3D to print, that’s why “Disp. PrtDlgBox” doesn’t help – the IW3D starts again and again asks a print dialog…