Hi Amber, there are a couple of reasons I know of that would cause a book to have two ISBNs. One would be that there is an ISBN for paperback and another for hardcover. The other reason is that one number has the old ten digit format and the other has the new 13 digit format. somewhere in the distant past bookshare said the thirteen digit number was preferable but the ten digit number would be accepted. The thirteen digit number should be shown as a solid number without any dashes or spaces. I have probably told you stuff you already know, but I hope some of this helps. Mike ----- Original Message ----- From: Amber To: bksvol-discuss@xxxxxxxxxxxxx Sent: Saturday, September 26, 2009 2:41 PM Subject: [bksvol-discuss] trouble. I am having trouble submiting, my book, it is called, Call Waiting by r L Stine, the problem is it has to ISBN numbers and i get an airer message, amber, G.