FF和Opera中的jquery draggable（）无法正常工作

Question

我在iframe表中有draggable和droppable（jquery）。它在chrome中的工作正常，但是当我想在FF中拖放时，我必须点击2次才能更改trs。

    $(this).draggable({ helper: 'clone', iframeFix: true, cursor: "move", cursorAt: { top: 600, left: 155 } });

                  $(childrensDraggableZone).droppable({
                      accept: '.dragdrop',
                      activeClass: "ui-state-hover",
                      hoverClass: "ui-state-active",
                      drop: function(event, ui) {

                          var draggable = ui.draggable, droppable = $(this),
                              dragPos = draggable.position(), dropPos = droppable.position();
                          draggable.css({
                                  left: dropPos.left + 'px',
                                  top: dropPos.top + 'px'
                              });

                          droppable.css({
                                  left: dragPos.left + 'px',
                                  top: dragPos.top + 'px'
                              });
                          draggable.swap(droppable);
                      }
                  });