Extra confusion
The bit of the user guide quoted by rcentros has: 'To page forward in a book, press the top button. To go back in a book, press the bottom button'
The full user guide linked in the first post has: 'To page forward in a book, press the botton button. To go back in a book, press the top button'
The rest of the paragraph is the same. That's in chapter 1 Getting Started and the picture has the buttons on the right-hand side.