I'm trying to create a book in iPhoto.

I dragged the photos I want to use to the book name in the source list. Now when I drag my photos to the actual book is when I have a problem.

What I figured out is that any time I tried to add a photo that I modified (enhanced, red-eye, color, etc.) it won't let me add it to the book. There is an exlamation point there instead of the picture. It works fine with pictures I haven't modified.

Is there something I have to do or is there some way around this?