Masonry and Safari giving bug

Question

To the Masonry work in safari I must add something?

For I have the following situation:

Picture 1- Safari NOK only one columns

Image 2- Chrome OK two columns

Code to call the masonry

  var $container = $('#container-masonry');
    // initialize
    $container.imagesLoaded( function() {
      $container.masonry({
        columnWidth: 540,
        itemSelector: '.item',
        isFitWidth: true,
        gutter: 60
      });

/*.container{ width: 1280px; }*/
  /*#container-masonry{ width: 1200px; }*/
  #container-masonry .item{ width: 540px; }

  .grid-sizer { width: 100% !important; }

  @media screen and (min-width: 720px) {
    /* 10 columns for larger screens */
    .grid-sizer { width: 540px; }
  }