diff --git a/gdk/quartz/gdkscreen-quartz.c b/gdk/quartz/gdkscreen-quartz.c
index 050267cc9b..30cd73edda 100644
--- a/gdk/quartz/gdkscreen-quartz.c
+++ b/gdk/quartz/gdkscreen-quartz.c
@@ -82,6 +82,13 @@ gdk_screen_set_default_colormap (GdkScreen   *screen,
     g_object_unref (old_colormap);
 }
 
+/* FIXME: note on the get_width() and the get_height() methods.  For
+ * now we only support screen layouts where the screens are laid out
+ * horizontally.  Mac OS X also supports laying out the screens vertically
+ * and the screens having "non-standard" offsets from eachother.  In the
+ * future we need a much more sophiscated algorithm to translate these
+ * layouts to GDK coordinate space and GDK screen layout.
+ */
 gint
 gdk_screen_get_width (GdkScreen *screen)
 {
@@ -221,6 +228,8 @@ screen_get_monitor_geometry (GdkScreen    *screen,
   NSArray *array;
   NSScreen *nsscreen;
   NSRect rect;
+  NSRect largest_rect;
+  int i;
 
   GDK_QUARTZ_ALLOC_POOL;
 
@@ -229,10 +238,31 @@ screen_get_monitor_geometry (GdkScreen    *screen,
   rect = [nsscreen frame];
   
   dest->x = rect.origin.x;
-  dest->y = rect.origin.y;
   dest->width = rect.size.width;
   dest->height = rect.size.height;
 
+  /* FIXME: as stated above the get_width() and get_height() functions
+   * in this file, we only support horizontal screen layouts for now.
+   */
+
+  /* Find the monitor with the largest height.  All monitors should be
+   * offset to this one in the GDK screen space instead of offset to
+   * the screen with the menu bar.
+   */
+  largest_rect = [[array objectAtIndex:0] frame];
+  for (i = 1; i < [array count]; i++)
+    {
+      NSRect rect = [[array objectAtIndex:i] frame];
+
+      if (rect.size.height > largest_rect.size.height)
+        largest_rect = [[array objectAtIndex:i] frame];
+    }
+
+  if (largest_rect.size.height - rect.size.height == 0)
+    dest->y = 0;
+  else
+    dest->y = largest_rect.size.height - rect.size.height + largest_rect.origin.y;
+
   if (in_mm)
     {
       dest->x = get_mm_from_pixels (nsscreen, dest->x);
diff --git a/gdk/quartz/gdkwindow-quartz.c b/gdk/quartz/gdkwindow-quartz.c
index 019201969e..86945cd57d 100644
--- a/gdk/quartz/gdkwindow-quartz.c
+++ b/gdk/quartz/gdkwindow-quartz.c
@@ -654,9 +654,16 @@ _gdk_quartz_window_is_ancestor (GdkWindow *ancestor,
 gint 
 _gdk_quartz_window_get_inverted_screen_y (gint y)
 {
-  NSRect rect = [[NSScreen mainScreen] frame];
+  int index;
+  GdkRectangle gdk_rect;
+  NSScreen *main_screen = [NSScreen mainScreen];
+  NSRect rect = [main_screen frame];
 
-  return rect.size.height - y;
+  index = [[NSScreen screens] indexOfObject:main_screen];
+
+  gdk_screen_get_monitor_geometry (_gdk_screen, index, &gdk_rect);
+
+  return gdk_rect.height - y + rect.origin.y + gdk_rect.y;
 }
 
 static GdkWindow *