How do I get thumbnails in Preview to Auto-Open?

Recently switched from Snow Leopard to Mountain Lion. I've adapted to many of the changes, but one thing I am finding horribly inconvenient is in Preview. I do a lot of PDF work in Preview, and every time I open a new file, I then have to select thumbnails in the sidebar to open them. I am used to them always opening like they did in Snow Leopard. Does anyone know a way I can reconfigure Mountain Lion to always open the selected file with the page thumbnails showing?

Thanks.