My book was just put on the iTunes store and I now relized I made a stupid mistake on the screen shots, you can see the text editing stuff (red line under an unusual spelling of a word, the blue lines etc).
Note that you cannot update screenshots yourself. From this kb article:
Note: You cannot update the screenshots that appear with your book in the iBookstore via a redelivery. You can only add screenshots to iTunes Producer the first time you publish your book. If you wish to amend your screenshots, use Contact Us in iTunes Connect.