All other applications print the correct number of copies via the Canon MX340 - correct?
And only the Printshop Pro Publisher Deluxe 20 application always wants to print out 199 copies whenever you have specified more than one copy.
Does that apply to all Printshop Pro documents or just one (or certain documents) in particular. Or some template perhaps?
When did the problem start: maybe some buggy update in Printshop Pro? Check Printshop's FAQs and Forums. Or contact their support directly. Especially if you are paying for support.
One thought I have is that maybe there is something in the Printshop document(s) imitating PCL (printer control language) that the Canon is interpreting as "print 199 copies". Some image or graphic. Occurs early on but why that would not happen with "print one copy" I do not know. The inconsistency is puzzling...
Try parsing through the document and only printing specific sections and pages. Use preview to see if the printer sets up for 199 pages. Cancel if so, and try another smaller section within the first attempt. See if you can narrow down to a certain portion of the document.