title: jquery-ui sortable: elements dragged behind when using multiple sortables
body: <p>I have a series of nested sortable elements exhibiting some strange behaviour with z-indexes.</p>
  
  <p>Basically, on some occasions elements are dragged behing the parent containers. It appears only after parent element has been sorted.</p>
  
  <p>It also looks like the behind problem is only on elements further down the list. So I can drag to a "higher" sortable, but dragging to a "lower" sortable and the drag element is suddenly behind. </p>
  
  <p><strong>Details:</strong></p>
  
  <p>Given
    sortable list <strong>A</strong> 
    each element in A in turns contains a connect sortable list <strong>B</strong> (as in the B lists in each A are all connected)</p>
  
  <p>After sorting an element in A, elements dragged from the sortable living in this list are now behind the other A elements.</p>
  
  <p>I have played around with the various z-index options via both CSS and Jquery to no avail.</p>