When you pick the option to have your taskbar hide, do you still see like a pixel of it poking out? I do, and its annoying, But i see that your screenshot doesnt, how did you do that?
If you really want to hide your taskbar like mine, There are lots of ways to do that.
One of them (which I did in this shot) is Jason's rainmeter skin [link]. It includes a skin that allows you to hide or show your taskbar. What I mean by hide is it is really hidden! .
There are more ways out there but this is the most simple way that I can give you.