iBooks crashes whenever it sees that particular book, even if it's just in a list of books. I tried re-pushing the book to DropBox and re-exporting/importing the book from DropBox to iBooks, but I'm seeing the same result.
There are many clues pointing to that one book as the culprit. For example, if I'm looking at a list of books none of the books from that one onward show cover images. (Of course, iBooks crashes shortly thereafter.)
This is a big problem because I can't even delete the book. To delete the book I have to select it first, and selecting it crashes iBooks...
I'm using iOS 8.1 on an iPad 2 and I'm using EPUB in iBooks.
Sorry for my delay in responding to you. The ebooks team has fixed this issue, and you might need to re-download the ebook to get it to display correct. We really appreciate your interest in our ebooks and have a great day!