Read Thread: "split clues"
Hmm.... On my computer, a text size of "normal" does the trick. It might be that the print area of your printer is different than mine, but it could also be that your page settings might have wider margins than mine as well.
But I figure that normal-size text ought to be small enough to break into two columns and as far as I'm concerned, it's a bug that it's not! So I changed the minimum width for a column to be from 25 ems to 20 ems. Hopefully that should fix it for you.
I kind of want to retire the screen and print text size preferences completely because browsers already do that so well on their own. Often time, better than AQ can do it since AQ doesn't know how wide your browser is but your browser does know! And browsers will increase the size of photos and icons which AQ generally doesn't. Not to mention that AQ doesn't really add much in terms of functionality. Seems like it would be a lot less complicated just to hand that job over the browser and ditch those options completely from AQ.