(also posted in PDF generation forum, I'm not sure which is most appropriate)
(ale: i've removed the other post: the section is not so important)
I created a document in Scribus and exported it as a PDF which *definitely* has equal outer margins on its left- and right-hand pages (I've triple checked this). However, having ordered a couple of printed draft copies from Lulu.com on separate occasions (I've generally been happy with them in the past), they both feature a margin-related anomaly - I'm assuming this isn't a printing error, as the problem is exactly the same in both copies.
The problem is this: on alternating spreads, the margin is either too-small-on-the-left-hand-page-and-too-big-on-the-right-hand-page, or the other way around. So it's like the entire content of each spread has been shifted about 5 or 6mm to the left or right, in alternation.
Does anyone have any idea what caused this, or what I can do to fix it? Is it something to do with PDF settings, or something at the Lulu end?