GtkCellRenderer does not update

[David Emory Watson <dwatson cs ucr edu>]

Neither of the two calls below cause the cell renderer to update
itself.  Is this a bug in gtk or do I need to do something to explicit
to get the cells to update?

        GtkCellRendererText *file_name_cell;

	...

        g_object_set (file_name_cell,
                      "scale", PANGO_SCALE_XX_LARGE,
                      NULL);

        gtk_cell_renderer_set_fixed_size (GTK_CELL_RENDERER
(file_name_cell),
        -1, row_height[view->details->zoom_level]);

Thanks in advance,
David