ui.position - avoid to resize parent window

ui.position - avoid to resize parent window

Hi.
when I am using ui.position the parent window has been resized. I moved elements as follows:

  1.       $( ".flexslider" ).position({
              my: "right bottom",
              at: "right bottom",
              of: ".region-main-upper"
          });

Now there is an empty area above the flexslider window which was moved down.

How do I avoid that?

test site