.position only runs on Firefox

.position only runs on Firefox

Hi.
I am working with Drupal 7.36 and Jquery 1.10.

The script:

  2. (function ($) {
  3.   Drupal.behaviors.moveFlexsliderAtTheRightPlace= {
  4.     attach: function (context, settings) {
  5.       $( ".flexslider" ).position({
  6.           my: "right bottom",
  7.           at: "right bottom",
  8.           of: ".region-main-upper"
  9.       });
  10.       $( "#block-superfish-1" ).position({
  11.           my: "left bottom",
  12.           at: "left bottom",
  13.           of: ".region-main-upper"
  14.       });
  15.       $( ".view-logo" ).position({
  16.           my: "left center",
  17.           at: "left center-100",
  18.           of: ".region-main-upper"
  19.       });
  20.     }
  21.   };
})(jQuery);

In Firefox every div appears at the right place. Unfortunately it didn't work in Chrome and Safari.