Hello, In my application I use to "post" a pointer to a dynamically allocated boost::function to a hidden window in the following manner (WinXP, MSVC9.0, 1.41): typedf function<void(void)> Functor; #define AM_FUNCTOR (WM_USER+79) // called from some "worker" thread void post(const Functor &func) { Functor *f = new Functor(func); PostMessage(hWind_, AM_FUNCTOR, 0, reinterpret_cast<LPARAM>(f)); } // Window procedure, called from the window thread LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam) { switch(msg) { case AM_FUNCTOR: { Functor *f = reinterpret_cast<Functor *>(lParam); (*f)(); delete f; } //.... } post() is called several times per second. Sometimes - but *very* rarely - the line "delete f" causes a crash (Access violation reading location 0xfeeefef6). The application is compiled with /Ox /GL, linked with /LTCG. What could be wrong with this code? Callstack: function_base.hpp, line 323: functor_manager_common::manage_small(): reinterpret_cast<functor_type*>(&out_buffer.data)->~Functor(); // THIS LINE CRASHES function_base.hpp, line 432: functor_manager::manage(): manager(in_buffer, out_buffer, op, tag_type()); The assembly code looks like this: 100134C9 mov esi,dword ptr [esi+0Ch] 100134CC test esi,esi 100134CE je boost::detail::function::functor_manager_common::manage_small+9Eh 100134D0 mov eax,dword ptr [esi] 100134D2 mov ecx,dword ptr [eax+8] // CRASHES HERE, as eax == 0xfeeefeee 100134D5 push esi 100134D6 call ecx Thanks in advance.