title: event dragmove and targetNode returns undefined
body: <p>I'm doing my first project in kineticJS; I have to drag some shapes on the canvas and in the meanwhile, I have to write somewhere on the page the coordinates of the shape in real time. In order to do this I use the event "dragmove" on the layer like this:</p>
  
  <pre><code>layer.on("dragmove",function(evt) {//detect shape and write stuff});
  </code></pre>
  
  <p>I used "targetNode" for catching the clicked shape.
  The problem is this: if I use targetNode on a shape that is not part of any group, everything works, but if the node that has to be moved is part of a group, targetNode only works the first time and then return an undefined value for all times following (dragmove usually takes some time, not like dragstart or click).</p>
  
  <p>I made a fiddle so you can see what I'm talking about:</p>
  
  <p><a href="http://jsfiddle.net/UScmU/" rel="nofollow">http://jsfiddle.net/UScmU/</a></p>
  
  <p>The 2 rects are in a group. if you click on a shape, an alert return its name, if you drag the circle or the rects, on the console will be written the shape's name.</p>
  
  <p>I would appreciate some help. sorry for my english, I also hope the text is understandable.</p>