add: this.mCurrentDropPosition = this.determineDropPosition(aEvent); 
context:   onDragEnter: function (aEvent, aDragSession)  {    var target = aEvent.target;    if (target.localName == "menupopup" || target.localName == "hbox")      target = target.parentNode;    if (aDragSession.canDrop) {      this.onDragSetFeedBack(aEvent);      this.onDragEnterSetTimer(target, aDragSession);    }    this.mCurrentDragOverTarget = target;    return;  },
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/8c7da050d905071c1126544567201890594b3197/navigatorDD.js/buggy/xpfe/browser/resources/content/navigatorDD.js