             
             // clearing the gridDimensions resets rowCount
             gridDimensions.rowCount = _dataProvider ? _dataProvider.length : 0;
-            gridDimensions.columnCount = _columns ? _columns.length : 0;
         }
         
         // Reset content size so scroller's viewport can be resized.  There

                gridSelection.removeAll();
                gridSelection.requireSelection = savedRequireSelection;
            }
            
           clearGridLayoutCache(columnsChanged);            
            
            if (!caretChanged)
                initializeCaretPosition();

                break;
            }                                
        }

        gridDimensions.columnsCollectionChanged(event);
        if (dataProvider)
            gridDimensions.rowCount = dataProvider.length;
        
        if (gridLayout)
            gridLayout.columnsCollectionChanged(event);
