Book cover margins are shifted on .pdf upload?!?

I've made at least six beautiful books using Aperture and NEVER had this problem. Now, no matter what I do, every time I try previewing my book the cover and hardback cover pages are shifted/truncated. The other 92 pages look fabulous! What the heck? The email I got from support did not work. Does anyone have other suggestions? Ever have this happen? I'm really bummed and not a little frustrated - having spent a long time putting that man pages together...

Thanks.