Prevent drag drop of custom mimetype to EditText

I have a custom mime type which I am intending to use to drag and drop application objects within the app. This seems to be working but I'm finding that the EditText fields are also accepting the drop action. I don't want this to happen.

First, I've defined the custome mime type like this:

public static final String MIME_TYPE_MYNODE = "com.example.mockup/mynode";

Then, in the onTouch handler for the source object I have:

  @Override
  //-----------------------------------------------------------------------------
  public boolean onTouch (View v, MotionEvent e)
  {
    ...
    else if (e.getAction() == MotionEvent.ACTION_MOVE)
    {
      String[] mimeTypes = {MIME_TYPE_MYNODE};
      ClipData data = new ClipData ("Task Tamer Note", mimeTypes, new ClipData.Item ("unused"));
      View.DragShadowBuilder shadow = new View.DragShadowBuilder(this);
      Object localState = v;
      startDrag (data, shadow, localState, 0);
      return false;
    }
  }
  ...
}

When I "drop" on an EditText widget, it inserts "unused" into the text area. How can I prevent this? Thanks.