Hi, The boost version is the Version_1_31_0 tag from the CVS repository. The VC version is 7.1.3088. Compiling foo.cpp (attached) results in the error reported in BuildLog.htm (attached). The VC options are also in the BuildLog.htm Uncommenting the line in foo.cpp that that begs you to, results in a clean compile. Has anybody else encountered this sort of weirdness?? I'm getting a lot of related behaviour, but this one is simple. #include <boost/python.hpp> using namespace boost::python; class World { public: World(std::string msg): msg(msg) {} // added constructor void set1(std::string msg) throw(std::exception) { this->msg = msg; } void set2(std::string msg) { this->msg = msg; } private: std::string msg; }; void wrap_World(class_<World> &foobar) { // foobar.def("set2", &World::set2); // OK, uncomment this and the compilation works!! foobar.def("set1", &World::set1); // Error on VC7.1 }