Individual update for an iBook purchase not allowing update

I recently purchased an iBook (Wheelmen) on my iPad using iBooks in iOS 7.1 and shortly after Ian update to the book came out. I downloaded the update and now a second update has shown up in my purchased section of my books account. I tried downloading it but it won't allow me to select the update to the book.

I tried a power cycle, tried shutting iPad on/off, logged out and back in with my Apple ID but update still shows and won't allow me to select and update. It just shows downloaded but still shows an update for it.

Could there be a second update or am I just not able to update it again?

Any thoughts how to clear the update or update if in fact it is a second update to the book?

Thanks.