diff -p -up gtkmm-2.15.0/gtk/gtkmm/messagedialog.cc~ gtkmm-2.15.0/gtk/gtkmm/messagedialog.cc
--- gtkmm-2.15.0/gtk/gtkmm/messagedialog.cc~	2008-12-22 22:04:21.000000000 +0100
+++ gtkmm-2.15.0/gtk/gtkmm/messagedialog.cc	2009-01-05 09:29:05.000000000 +0100
@@ -72,9 +72,9 @@ void MessageDialog::set_message(const Gl
 void MessageDialog::set_secondary_text(const Glib::ustring& text, bool use_markup)
 {
   if(use_markup)
-    gtk_message_dialog_format_secondary_markup(gobj(), text.c_str());
+    gtk_message_dialog_format_secondary_markup(gobj(), "%s", text.c_str());
   else
-    gtk_message_dialog_format_secondary_text(gobj(), text.c_str());
+    gtk_message_dialog_format_secondary_text(gobj(), "%s", text.c_str());
 }
 
 } // namespace Gtk