Hi Tedkl,
Welcome to the HP Forums!
I have read your post on printing blank pages with a printed code in the corner of the pages, and I would be happy to assist you in this endeavor!
I researched the error code 2345X and found that there is a Critical HP Print Driver Update to address printing of an extraneous page. If this patch still does not resolve the issue, you may need to reset the printing system to re-establish the photosmart print queue on the Mac.
Thank you for visiting the HP Forums, and I look forward to your reply!