WordPress wp_editor jquery drag drop offset issue

I’m having an issue with the following code:

i’m initializing an tinyMCE editor in WordPress:

    wp_editor("<div>HTML content</div>", "id-of-editor", $settings);

This generates an tinyMCE editor within an iframe. Inside that iframe i have a dropppable jquery ui div.

I want to drop content from outside the iframe, into the iframe.

So far i have made this:

$( "#drag" ).draggable({ 
            helper: "clone",
            revert:"valid",iframeFix:true 
         });


$("#editor-iframe").contents().find(".droppable-div").droppable({                     

         accept: "#drag",

    });      

Everything works, except for one thing. There is a 150px offset between the cursor position, and the real drag position.

Because of this, the drag event only is detected when i put the draggable item far away from the droppable zone.

Any help ?

Thanks in advance. Sorry for my bad english! It’s not my native language.

Image Description of the problem:
http://i.stack.imgur.com/4hGfW.jpg