title: Editing textarea breaks Droppable
body: <p>I'm trying to drag content into a textarea using prototype/scriptaculous, edit the text area, and then continue to drag and drop some more content. Dragging and dropping works fine, but as soon as I edit the content in the textarea, dropping ceases working.</p>
  <p>I wrenched it down into a <a href="http://jockelhofmann.de/dragdrop.html" rel="nofollow noreferrer">test case</a></p>
  <pre><code>&lt;!DOCTYPE HTML PUBLIC &quot;-//W3C//DTD HTML 4.01 Transitional//EN&quot;
     &quot;http://www.w3.org/TR/html4/loose.dtd&quot;&gt;
  &lt;html&gt;
      &lt;head&gt;
          &lt;title&gt;dragdrop testcase&lt;/title&gt;
          &lt;script type=&quot;text/javascript&quot; src=&quot;/shoppingZend/public/javascript/scriptaculous/lib/prototype.js&quot;&gt;&lt;/script&gt;       
          &lt;script type=&quot;text/javascript&quot; src=&quot;/shoppingZend/public/javascript/scriptaculous/src/scriptaculous.js?load=effects,dragdrop,controls&quot;&gt;&lt;/script&gt;
      &lt;/head&gt;
      &lt;body&gt;
          &lt;div id=&quot;content_1&quot; class=&quot;drag&quot;&gt;Content 1&lt;/div&gt;
          &lt;div id=&quot;content_2&quot; class=&quot;drag&quot;&gt;Content 2&lt;/div&gt;
          &lt;div id=&quot;content_3&quot; class=&quot;drag&quot;&gt;Content 3&lt;/div&gt;
          &lt;textarea id=&quot;drop&quot;&gt;&lt;/textarea&gt;
          &lt;script&gt;
              new Draggable('content_1', {
                  revert: true
              });
  
              new Draggable('content_2', {
                  revert: true
              });
  
              new Draggable('content_3', {
                  revert: true
              });
  
              Droppables.add(
                  'drop', {
                      onDrop: function(dragged, dropped, event) {
                          dropped.innerHTML += dragged.innerHTML;
                      }
                  }
              );
          &lt;/script&gt;
      &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  <p>Just in case of it being a browser problem (which I doubt it to be): I'm only using Firefox on Linux, it's a very private site and does not need to work anywhere else.</p>
  <p>Any idea where I could start debugging?</p>