I've been looking through the template instantiation trace, and I can't figure out where the choice to use the intrusive mechanism is made. I'll keep looking a little more, and I've appended the trace below: ------ Build started: Project: NewClient, Configuration: Debug Win32 ------ Compiling... EnhancedMessageHandler.cpp c:\D2\API\NewClient\EnhancedMessageHandler.cpp(151) : warning C4244: '=' : conversion from 'uintptr_t' to 'unsigned long', possible loss of data c:\new_boost\boost\boost\serialization\access.hpp(107) : error C2039: 'serialize' : is not a member of 'Jrs::SmartPtr<T>' with [ T=D2::Message ] c:\new_boost\boost\boost\serialization\serialization.hpp(81) : see reference to function template instantiation 'void boost::serialization::access::serialize<Archive,T>(Archive &,T &,const unsigned int)' being compiled with [ Archive=boost::archive::text_oarchive, T=const D2::MessagePtr ] c:\new_boost\boost\boost\serialization\serialization.hpp(140) : see reference to function template instantiation 'void boost::serialization::serialize<Archive,T>(Archive &,T &,const unsigned int)' being compiled with [ Archive=boost::archive::text_oarchive, T=const D2::MessagePtr ] c:\new_boost\boost\boost\archive\detail\oserializer.hpp(152) : see reference to function template instantiation 'void boost::serialization::serialize_adl<Archive,T>(Archive &,T &,const unsigned int)' being compiled with [ Archive=boost::archive::text_oarchive, T=const D2::MessagePtr ] c:\new_boost\boost\boost\serialization\extended_type_info_typeid.hpp(71) : while compiling class-template member function 'void boost::archive::detail::oserializer<Archive,T>::save_object_data(boost:: archive::detail::basic_oarchive &,const void *) const' with [ Archive=boost::archive::text_oarchive, T=D2::MessagePtr ] c:\new_boost\boost\boost\archive\detail\oserializer.hpp(236) : see reference to class template instantiation 'boost::archive::detail::oserializer<Archive,T>' being compiled with [ Archive=boost::archive::text_oarchive, T=D2::MessagePtr ] c:\new_boost\boost\boost\archive\detail\oserializer.hpp(235) : while compiling class-template member function 'void boost::archive::detail::save_non_pointer_type<Archive,T>::save_standard: :invoke(Archive &,const Jrs::SmartPtr<D2::Message> &)' with [ Archive=boost::archive::text_oarchive, T=D2::MessageP tr ] c:\new_boost\boost\boost\archive\detail\oserializer.hpp(294) : see reference to class template instantiation 'boost::archive::detail::save_non_pointer_type<Archive,T>::save_standard ' being compiled with [ Archive=boost::archive::text_oarchive, T=D2::MessagePtr ] c:\new_boost\boost\boost\archive\detail\oserializer.hpp(282) : while compiling class-template member function 'void boost::archive::detail::save_non_pointer_type<Archive,T>::invoke(Archive &,const Jrs::SmartPtr<D2::Message> &)' with [ Archive=boost::archive::text_oarchive, T=D2::MessagePtr ] c:\new_boost\boost\boost\archive\detail\oserializer.hpp(534) : see reference to class template instantiation 'boost::archive::detail::save_non_pointer_type<Archive,T>' being compiled with [ Archive=boost::archive::text_oarchive, T=D2::MessagePtr ] c:\new_boost\boost\boost\archive\basic_text_oarchive.hpp(78) : see reference to function template instantiation 'void boost::archive::save<Archive,T>(Archive &,T &)' being compiled with [ Archive=boost::archive::text_oarchive, T=const D2::MessagePtr ] c:\new_boost\boost\boost\archive\detail\interface_oarchive.hpp(89) : see reference to function template instantiation 'void boost::archive::basic_text_oarchive<Archive>::save_override<T>(T &,int)' being compiled with [ Archive=boost::archive::text_oarchive, T=const D2::MessagePtr ] c:\D2\API\NewClient\EnhancedMessageHandler.cpp(115) : see reference to function template instantiation 'Archive &boost::archive::detail::interface_oarchive<Archive>::operator <<<const D2::MessagePtr>(T &)' being compiled with [ Archive=boost::archive::text_oarchive, T=const D2::MessagePtr ]