Damn! Win32 Graph/graph has been failing for Intel and Microsoft since sometime Friday! That's a showstopper. Quick response would be greatly appreciated. --Beman The VC++7.1 error message begins: D:\boost-snapshot\boost\graph\detail\adjacency_list.hpp(1325) : error C2440: 'initializing' : cannot convert from 'std::_Tree<_Traits>::const_iterator' to 'std::_Tree<_Traits>::iterator' with [ _Traits=std::_Tset_traits<boost::detail::adj_list_gen<boost::adjacency_list<boost::setS,boost::setS,boost::undirectedS,boost::property<vertex_id_t,size_t>,boost::property<edge_id_t,size_t>>,boost::setS,boost::setS,boost::undirectedS,boost::property<vertex_id_t,size_t>,boost::property<edge_id_t,size_t>,boost::no_property,boost::listS>::config::StoredEdge,std::less<boost::detail::adj_list_gen<boost::adjacency_list<boost::setS,boost::setS,boost::undirectedS,boost::property<vertex_id_t,size_t>,boost::property<edge_id_t,size_t>>,boost::setS,boost::setS,boost::undirectedS,boost::property<vertex_id_t,size_t>,boost::property<edge_id_t,size_t>,boost::no_property,boost::listS>::config::StoredEdge>,std::allocator<boost::detail::adj_list_gen<boost::adjacency_list<boost::setS,boost::setS,boost::undirectedS,boost::property<vertex_id_t,size_t>,boost::property<edge_id_t,size_t>>,boost::setS,boost::setS,boost::undirectedS,boost::property<vertex_id_t,size_t>,boost::property<edge_id_t,size_t>,! boost: : no_property,boost::listS>::config::StoredEdge>,false> ] and [ _Traits=std::_Tset_traits<boost::detail::adj_list_gen<boost::adjacency_list<boost::setS,boost::setS,boost::undirectedS,boost::property<vertex_id_t,size_t>,boost::property<edge_id_t,size_t>>,boost::setS,boost::setS,boost::undirectedS,boost::property<vertex_id_t,size_t>,boost::property<edge_id_t,size_t>,boost::no_property,boost::listS>::config::StoredEdge,std::less<boost::detail::adj_list_gen<boost::adjacency_list<boost::setS,boost::setS,boost::undirectedS,boost::property<vertex_id_t,size_t>,boost::property<edge_id_t,size_t>>,boost::setS,boost::setS,boost::undirectedS,boost::property<vertex_id_t,size_t>,boost::property<edge_id_t,size_t>,boost::no_property,boost::listS>::config::StoredEdge>,std::allocator<boost::detail::adj_list_gen<boost::adjacency_list<boost::setS,boost::setS,boost::undirectedS,boost::property<vertex_id_t,size_t>,boost::property<edge_id_t,size_t>>,boost::setS,boost::setS,boost::undirectedS,boost::property<vertex_id_t,size_t>,boost::property<edge_id_t,size_t>,! boost: : no_property,boost::listS>::config::StoredEdge>,false> ] No constructor could take the source type, or constructor overload resolution was ambiguous