Hi, I have started to write a ProxyServer that analyzes TDS-packages sent from the Microsoft SQLServer Management Studio to a MS SQLServer. It seems to work fine for one or two connections, but if more connections are openend, boost suddenly crashes, mostly in the bind-template.hpp: template<class A1, class A2> result_type operator()(A1 const & a1, A2 const & a2) { list2<A1 const &, A2 const &> a(a1, a2); CRASH ===> BOOST_BIND_RETURN l_(type<result_type>(), f_, a, 0); } I have modified the code from the examples page: http://www.boost.org/doc/libs/1_46_1/doc/html/boost_asio/example/echo/async_... I only added a second socket in the session class for handling the connection to the SQLServer. When I start SSMS and click on "New query", I can see two additional connections being opened, and then the program crashes. I have posted the source code here: session.h : http://pastebin.com/eC5fn7U8 session.cpp : http://pastebin.com/LDnQqCNr server.h: http://pastebin.com/1fDJU6sx server.cpp: http://pastebin.com/seMAVx4D ProxyServer.cpp: http://pastebin.com/8S7YfE8L Am I doing something wrong? Maybe the code isn't threadsafe? I'm new to boost::asio and I might have missed an important point here. Maybe I need more than one io_service object? Andi -- Using Opera's revolutionary email client: http://www.opera.com/mail/