Hi, In my code I have a io_Service and a work object shared among my classes: // Main io_service static boost::asio::io_service io_service; static boost::scoped_ptrboost::thread io_service_thread; static boost::asio::io_service::work* p_work; static BOOL thread_started; void io_worker_thread(void) { #if(WIN32 && _WIN32_DCOM) struct com_init { com_init() { CoInitializeEx(NULL, COINIT_APARTMENTTHREADED); } ~com_init() { CoUninitialize(); } } initializer_object; #endif io_service.run(); io_service.reset(); thread_started = false; }; void Init(....) { if (!thread_started) { try { // create the work object on the heap p_work = new boost::asio::io_service::work(io_service); // run the IO service as a separate thread: // Instead of start the worker thread directly // by passing the io_service object, // I call the io_worker_thread function where // I can do some initialization tasks like // calling CoInitializeEx for COM io_service_thread.reset(new boost::thread(io_worker_thread)); thread_started = !thread_started; } catch (boost::thread_resource_error e) { // Failed to create the new thread return 0; } } } When my application ends and the io_service.run() returns I get: First-chance exception at 0x09299c18 (AxEuroATLib_debug.dll) in EuroSvr.exe: 0xC0000005: Access violation reading location 0xf0f0f0fc. at the following line (io_service.ipp): inline io_service::work::~work() { io_service_.impl_.work_finished(); } I wrong something? Regards, Daniele