I ran some of my code through valgrind and it detected the use of an uninitialized value in the serialization library, as reported below: ==21969== Use of uninitialised value of size 8 ==21969== at 0x80A9CE3: void boost::archive::xml_oarchive_implboost::archive::xml_oarchive::save<double>(double const&) (xml_oarchive.hpp:53) ==21969== by 0x80A9CD6: void boost::archive::save_access::save_primitive(boost::archive::xml_oarchive&, double const&) (oserializer.hpp:97) ==21969== by 0x80A9CB1: boost::archive::detail::save_non_pointer_type::save_primitive::invokex(boost::archive::xml_oarchive&, double const&) (oserializer.hpp:217) ==21969== by 0x80A9C97: boost::archive::detail::save_non_pointer_type::invoke(boost::archive::xml_oarchive&, double const&) (oserializer.hpp:309) I took a peek at the code, but I can't see anything obviously wrong, so the report may be spurious. Bill