Sortable: Error when there are items in the sortable container that are already a sortable

In this example --> http://jsfiddle.net/4p8b6/

We configure some containers and items, and apply only the sortable widget to the containers, but one container is also "sortable", so we can move items between all containers.

Everything works ok, except when I move the inner container outside the parent boundaries, then the inner container dissapears and the following exception occur "5779Uncaught Error: HIERARCHY_REQUEST_ERR: DOM Exception 3"

I tried to solve it adding some conditions to _clean method in sortable widget

Original:

if (!this._noFinalSort && this.currentItem[0].parentNode) this.placeholder.before(this.currentItem);

Changed

if (!this._noFinalSort && 
            this.currentItem[0].parentNode && 
            this.currentItem[0].parentNode && 
            this.currentItem[0].parentNode.tagName != null &&
            this.placeholder[0].parentNode[$.expando] != this.currentItem[0][$.expando]) {
                
        this.placeholder.before(this.currentItem);
    }

Hope this helps.

Thanks in advance

Regards

Diego Parra