Urgent help needed with iPhoto/pdf preview for book order - mysterious pixelated areas show on PDF but not in iPhoto

Hello. I ordered an iPhoto book last week to give to my parents for their 50th wedding anniversary. Tonight, I just checked on the order status and found that my book is cancelled. I received no notification about it, and all I could do was fill out the online form, so customer service will get back to me on Monday via email (if I'm lucky...). There is no telephone number for me to call about this. I decided I'd best do some searching to try to figure out what had happened.

I had thought that the preview I saw in iPhoto was the preview of the book. I found out I was wrong. So I created a PDF preview of the book and found some craziness that I don't understand. In iPhoto (and any other program, i.e. PhotoShop), my photos are fine. They are mostly TIFF format and high resolution with a few high res JPEGs. However, when I view the PDF, there is a band of black and white pixelation about 1/2-inch across the bottom of some pages - not all. The photos in that area are messed up in that band zone. The other photos are totally unaffected. This affects both TIFF and JPEG photos, and both black and white and color.

Has anyone else had this problem, and what was your solution? I would be extremely grateful to anyone for advice or information about this! The anniversary party is less than a week away and I'm beyond my limit of stress right now...