I've had the same problem with an Ipad 2 and the new-ish update. Open a book, go to your Aa button at the top right, click it, click more options, set justification to off, publisher defaults to off, and animate page turns to off. You can leave two page landscape on if you want. This cleared my problem up. The book will still jump back a page if it changes orientation but I can deal with that.
Hope that helps!