Boost Asynchronous Timer not timing out

I have an application using the Boost library with the following code:

//Set up for wait and read.
wait_result = in_progress;


async_read_until(port,readData,io_params.delim,
                 boost::bind(&SerialComm::readCompleted,
                 this,boost::asio::placeholders::error,
                 boost::asio::placeholders::bytes_transferred));

timer.expires_from_now(boost::posix_time::milliseconds(1000));

timer.async_wait(boost::bind(&SerialComm::timeoutExpired,this,
                                 boost::asio::placeholders::error));


// This blocks until an event on io_service_ is set.


io_service_.run_one();

while(wait_result == in_progress){
    // Brackets in success case limit scope of new variables
    switch(wait_result){
    case success:{
        timer.cancel();
        // Remove the delimiter byte - don't want this.
        bytes_transferred -= 1;
        istream is(&readData);
        // Allocation of string
        string msg(bytes_transferred, '\0');

        is.read(&msg[0], bytes_transferred);
        // Remove the delimiter
        is.ignore(1);
        data_handler(msg);
        break ;}
     case timeout_expired:

        port.cancel();
        cout << "Time is up..." << endl;
        break ;
    case error_out:
        cout << "Serial port error read..." << endl;
        break ;
    case in_progress:
        break;
    }
}

where timer is a boost::asio::deadline_timer and the callback function timeoutExpired looks like:

void SerialComm::timeoutExpired(const boost::system::error_code &error){
    if (!error && wait_result == in_progress){wait_result = timeout_expired;}

}

The problem is that the callback function is not expiring. If I place a breakpoint in the callback function, it is never hit. If I put a watch on the timer variable, what I notice is that the expiry is exactly 6 h ahead of where it should be (I am assuming this is because it is UTC).

According to the boost documentation of the deadline_timer, the clock works in UTC, but this appeared to be functioning properly yesterday with no problem so I can assume that UTC is not the problem. Any ideas as to why this might not be firing properly?