Having a problem with the built-in PDF viewer.

I think it's supposed to be the same as Chrome's, but there's a problem I'm having with it when I use Opera. When I press the right arrow key, in a PDF presentation for example, it is supposed to go to the next page. It usually skips a page and goes forward 2 pages. Additionally, page numbers are usually off. If I scroll to the bottom of the content, the scroll bar on the right is about half way down as is the page number counter.

I'm assuming these problems are one and the same. Anyone have this (or better yet, solve it?)