dirty html (textarea) after grid.enableBlockSelection()

The method .enableBlockSelection() append a textarea to the body.
After each .load() or .post() the grid generates a new textarea.
After a while there are a lot of this. They will not removed, if the grid is destroyed.

It is generated by /ext/dhtmlxgrid_selection.js:

[code]
if (!window.dhx4.isIPad){
var area = this._clip_area = document.createElement(“textarea”);
area.style.cssText = “position:absolute; width:1px; height:1px; overflow:hidden; color:transparent; background-color:transparent; bottom:1px; right:1px; border:none;”;

area.onkeydown=function(e){
          e=e||event;
          if (e.keyCode == 86 && (e.ctrlKey || e.metaKey))
      self.pasteBlockFromClipboard()
};
  document.body.insertBefore(this._clip_area,document.body.firstChild);

  dhtmlxEvent(this.entBox,"click",function(){
      if (!self.editor && self._clip_area)
          self._clip_area.select();
  });

}[/code]

Why this comes with dhtmlx4x ? In lower versions this was not generated…
Is there a bugfix?

Greetings

Frank