Robert, The following warnings are the result of assigning int values to smaller data types in basic_binary_oarchive::save_overload. Any thoughts on clearing these up. Should these use numeric_cast? boost_1_37_0\boost/archive/basic_binary_oarchive.hpp(72) : warning C4244: 'initializing' : conversion from 'const unsigned int' to 'const unsigned char', possible loss of data boost_1_37_0\boost/archive/basic_binary_oarchive.hpp(77) : warning C4244: 'initializing' : conversion from 'const int' to 'const boost::int_least16_t', possible loss of data \boost_1_37_0\boost/archive/basic_binary_oarchive.hpp(82) : warning C4244: 'initializing' : conversion from 'const int' to 'const boost::int_least16_t', possible loss of data Thanks, Jeff