Jquery Draggable - center cursorAt Vertically

I also wanted to center my draggable objects after I pick them up. My solution:

$(".dragme").draggable({ 
    start: function(event, ui) { 
        $(this).draggable("option", "cursorAt", {
            left: Math.floor(this.clientWidth / 2),
            top: Math.floor(this.clientHeight / 2)
        }); 
    }
});

Worked around the initial problem, see the comment to my initial post.

EDIT:

Tolerance option "pointer": The mouse pointer overlaps the other item.

$(".sortable").sortable({
    containment: "parent",
    tolerance: "pointer"
});

This works fine if draggable have helper object. Just put it in start method of draggable as below code.

start: function(event, ui) { 
  $(this).draggable("option", "cursorAt", {
    left: Math.floor(ui.helper.width() / 2),
    top: Math.floor(ui.helper.height() / 2)
  }); 
}