Why can I not upload an assembled photo book to Apple?

I have created a photo book which has 76 pages. I am able to assemble the book and preview and save it as a pdf, but when I try and buy the book through Apple, my computer hangs when it gets to the Upload stage. I have tried clearing the cache and using different proxy servers, all to no avail. This is extremely frustrating as I have a deadline to get the book printed by. I can get no help from Apple as the call centre is not open on Sundays in Asia, and when I call the US number, it drops my call after promising to connect me to an apple expert!

Any ideas anyone?