iPhoto '11: Background images may not be scaled for extra-large hardcover books
After upgrading to iPhoto ’11 from iPhoto ’09, background images may not be scaled to fit the page in extra-large hardcover books.
This issue occurs in iPhoto when editing an extra-large hardcover book, or when previewing the PDF of the book. It will look like this:
To resolve this issue and have the backgrounds scaled to fit the page, choose Quit iPhoto from the iPhoto menu. Then, reopen the application. The background images should now be scaled correctly.