a case of unstable print setup

once a month I have to send ps-files written from about 14 Quark publications, one ps from one page, totalling 128 pages. I decided to script print setup as seen in the following code. Other scripts use this setup to print the pages from documents.
This month ONE of the publications was printed with a mistake - all pictures were spooled using 72 dpi resolution. The guys in the typography were rather upset, but now its too late anyway :/. Possibly someone of you came across this situation before, because I myself cannot work out, how it could be possible, as soon as print setup is the same for all of them. Thank you, - ev

-- print setup code

tell application "QuarkXPress 4.11"
	tell document 1
		tell print setup
			set separation to true
			set include blank pages to true
			set print spreads to false
			set page sequence to all pages
			set bleed to "5 mm"
			set registration marks to centered
			set registration marks offset to "5 mm"
			set adjust horizontal tile to false
			set back to front to false
			set collate to false
			set print thumbnails to false
			set tiling to off
			set printer type to "Tanto6120 K75 PPD"
			set paper width to "245 mm"
			set reduce or enlarge to 100
			set page position to center horizontal
			set fit in area to false
			set orientation to portrait
			set page gap to "0 mm"
			set paper offset to "0 mm"
			set halftone screen to 150
			set resolution to 2540
			set print colors as grays to true
			set flip horizontal to false
			set flip vertical to false
			set invert image to false
			set data format to binary data
			set print quality to normal
		end tell
	end tell
end tell

I got an idea that this might happen because I used 4-th version of Quark in MacOsX under emulation… As I see, here printers act like hell, those ones installed in OsX seem to be charge of the guys at Classic… Can’t get heads and tails of it. - Evg.