Notice when you click on these tabs, not only does the slide change, but so does the url bar. It will appear like "page.html#slidername". This is useful if someone wants to manually access a slide through a permalink, they can just type that in, hit enter and that slide will show up. Go ahead, click on a tab then hit the refresh button. If you don't want the page to jump down when you click a tab, I would suggest setting permalinking to false.