I have an application using boost::asio (v 1.35.0) that creates a udp multicast socket and an acceptor using an io_service and then calls io_service.run(). Additional sockets are created from acceptor.async_accept. My code needs to stop all the sockets and then restart them at a later point. When stopping the sockets, I close all the sockets I opened before deleting them. I then call io_service.stop(). When I restart things, I call io_service.reset(), recreate the udp multicast and acceptor sockets on the io_service and then call io_service.run(). When the io_service starts up again, it seems to have old operations on the queue and it tries to process them. I will usually get either a "vector iterator not dereferencable" error from a buffer on a deleted class or an error in a deleted version of the class that was processing async_accept before I stopped. Is there something additional I should be doing to clear the queue in the io_service? Thanks, John