Hi Dan,
Sorry for the delay; life getting in the way again! I appreciate your reply, and the trouble you have taken.
By any chance, are the instructions you are reading for a Windows machine? I'm on a Mac, and the dialogue boxes I get don't have any of the things you mention. I see a 'document setup' button in Designer, but none of the options in there match the setting you quoted, nor do I see any uncheckable boxes in the Layout section of the print driver.
In the print dialogue, I see a quality slider under 'Media & Quality' but it only has the choices of 'Draft - Normal - Best'; no custom options.
Unless I'm looking in the wrong place?