Index: gtktooltip.c
===================================================================
--- gtktooltip.c	(revision 21539)
+++ gtktooltip.c	(working copy)
@@ -440,6 +440,10 @@ gtk_tooltip_trigger_tooltip_query (GdkDi
   event.motion.y = y;
   event.motion.is_hint = FALSE;
 
+  gdk_window_get_origin (window, &x, &y);
+  event.motion.x_root = event.motion.x + x;
+  event.motion.y_root = event.motion.y + y;
+
   _gtk_tooltip_handle_event (&event);
 }
 
