Q: Dear Apple, Please help me with submitting my book to the iBooks Store.

You're not talking to Apple here, just other users like yourself.  Use the contacts listed at the bottom of the FAQ:

http://www.apple.com/itunes/working-itunes/sell-content/books/book-faq.html

Have you resolved this problem? 

You can try bypassing iBooks Author Publish -  if you are sure you have the correct exported final version of your book, open iTunes Producer and use the same ID as  the iBA "Publish" version,  then follow the  normal steps.

It really should not make a difference, but sometimes iBooks Authours "Publish"  function can advise errors that are none existant.

Hi John,

Please be aware that you are not talking directly to Apple; this is a place where regular Apple product users discuss and help each other.

Three weeks o since the op came on to the group with a problem... then  does not bother to come back and offer a thanks for the help,suggestions or advise the outcome - which  can be  information which  helps others.