What version of iPhoto do you have?
Have you tried previewing using this method -
Before ordering your book preview it using this method - http://support.apple.com/kb/HT1040 - and save the resulting PDF for reference - the delivered book will match it.
have you tried in safe mode?
What is the "error" yu get
Remember we know nothing except what you tell us do to be able to help you you must supply information
Thanks to this discussion - I was able to help a client successfully order her book after using Safe Boot. Then, based on JammerD's mention of a 3rd party application interfering... I looked about and found Mac Defender installed. We uninstalled it, rebooted computer, and were able to again sucessfully order a book, this time without using Safe Boot.