When printing a job from Scenicsoft Preps that contains data from QuarkXPress for PC, a PostScript error undefined Offending command pkng can show up. This problem is caused by one of two XTensions: PDF Nester and PDF Filter.
This bug is fixed in the PDF Filter 1.6 XTension. You can download it from Quark’s Web site. If you have the PDF Nester XTension, the solution is to disable it prior to creating PostScript files from QuarkXPress.