Get name destroys undo feature in quark

Hi all, everytime I run this script Quark 6.5’s undo feature disapears.
Has this happend to anybody else? Are there any workarounds?

Thanks!

Peter Karlsson


on run
	tell application "QuarkXPress Passport"
		
		set docString to (name of every document) as list
	end tell
	return docString
end run