===================================================================
--- 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.
+@@ -99,6 +99,8 @@
+
+ GtkSensitivityType lower_sensitivity;
+ GtkSensitivityType upper_sensitivity;
++
++ guint motion_idle;
+ };
+
+
+@@ -1721,6 +1723,16 @@
+ &handled);
+ }
+
++static gboolean
++update_slider_position_idle (GtkRange *range)
++{
++ update_slider_position (range, range->layout->mouse_x,range->layout->mouse_y);
++
++ range->layout->motion_idle = 0;
++
++ return FALSE;
++}
++
+ static void
+ stop_scrolling (GtkRange *range)
+ {
+@@ -1860,8 +1872,8 @@
+ if (gtk_range_update_mouse_location (range))
+ gtk_widget_queue_draw (widget);
+
+- if (range->layout->grab_location == MOUSE_SLIDER)
+- update_slider_position (range, x, y);
++ if (range->layout->grab_location == MOUSE_SLIDER && !range->layout->motion_idle)
++ range->layout->motion_idle = g_idle_add ((GSourceFunc)update_slider_position_idle, range);
+
+ /* We handled the event if the mouse was in the range_rect */
+ return range->layout->mouse_location != MOUSE_OUTSIDE;
