code: function(oColumn, index) {
      // Store scroll pos
      var hdPos = this._elHdContainer.scrollLeft;
      var bdPos = this._elBdContainer.scrollLeft;
      
      // Call superclass method
      var oNewColumn = SDT.superclass.insertColumn.call(this, oColumn, index);
      
      // Restore scroll pos
      this._elHdContainer.scrollLeft = hdPos;
      this._elBdContainer.scrollLeft = bdPos;
      
      return oNewColumn;
  }
docs: Inserts given Column at the index if given, otherwise at the end. NOTE: You
  can only add non-nested Columns and top-level parent Columns. You cannot add
  a nested Column to an existing parent.
  
  @method insertColumn
  @param oColumn {Object | YAHOO.widget.Column} Object literal Column
  definition or a Column instance.
  @param index {Number} (optional) New tree index.
  @return oColumn {YAHOO.widget.Column} Inserted Column instance.