diff --git a/src/run-metacity.sh b/src/run-metacity.sh
index a1fd82be7..8c861113a 100755
--- a/src/run-metacity.sh
+++ b/src/run-metacity.sh
@@ -12,6 +12,8 @@ if test -z "$SCREENS"; then
   SCREENS=1
 fi
 
+MAX_SCREEN=`echo $SCREENS-1 | bc`
+
 if test "$DEBUG" = none; then
   DEBUG=
 elif test -z "$DEBUG"; then
@@ -56,7 +58,7 @@ if test -z "$ONLY_WM"; then
 
   echo "Launching clients"
   if test -n "$TEST_CLIENT"; then
-      for I in `seq 0 $SCREENS`; do
+      for I in `seq 0 $MAX_SCREEN`; do
           DISPLAY=$CLIENT_DISPLAY.$I $TEST_CLIENT &
       done
   fi
@@ -81,7 +83,7 @@ if test -z "$ONLY_WM"; then
  
   usleep 50000
 
-  for I in `seq 0 $SCREENS`; do
+  for I in `seq 0 $MAX_SCREEN`; do
       DISPLAY=$CLIENT_DISPLAY.$I xsetroot -solid royalblue3
   done
 fi
diff --git a/src/stack.c b/src/stack.c
index 22b1baa5f..0e6ae3738 100644
--- a/src/stack.c
+++ b/src/stack.c
@@ -408,6 +408,7 @@ ensure_above (MetaWindow *above,
     {
       /* move above to below->stack_position bumping below down the stack */
       meta_window_set_stack_position (above, below->stack_position);
+      g_assert (below->stack_position + 1 == above->stack_position);
     }
 
   meta_topic (META_DEBUG_STACK, "Above pos %d > below pos %d\n",
diff --git a/src/tools/metacity-window-demo.c b/src/tools/metacity-window-demo.c
index f4bd7ffc3..0102fbeca 100644
--- a/src/tools/metacity-window-demo.c
+++ b/src/tools/metacity-window-demo.c
@@ -225,6 +225,7 @@ make_dialog (GtkWidget *parent,
              int        depth)
 {
   GtkWidget *dialog;
+  char *str;
   
   dialog = gtk_message_dialog_new (GTK_WINDOW (parent),
                                    GTK_DIALOG_DESTROY_WITH_PARENT,
@@ -233,6 +234,10 @@ make_dialog (GtkWidget *parent,
                                    "Here is a dialog %d",
                                    depth);
 
+  str = g_strdup_printf ("%d dialog", depth);
+  gtk_window_set_title (GTK_WINDOW (dialog), str);
+  g_free (str);
+  
   gtk_dialog_add_button (GTK_DIALOG (dialog),
                          "Open child dialog",
                          GTK_RESPONSE_ACCEPT);