Index: gtk/gtkrange.c
===================================================================
--- gtk/gtkrange.c	(revision 18523)
+++ gtk/gtkrange.c	(working copy)
@@ -1979,8 +1979,12 @@
       gtk_widget_queue_draw (GTK_WIDGET (range));
       
       /* This is so we don't lag the widget being scrolled. */
+#if 0
+      /* Disable this, the scroll bar lags a bit but the end result is that
+         scrolling treeviews is *a lot* smoother. See GNOME #460534. */
       if (GTK_WIDGET_REALIZED (range))
         gdk_window_process_updates (GTK_WIDGET (range)->window, FALSE);
+#endif
     }
   
   /* Note that we don't round off to range->round_digits here.