Re: [Boost-users] [asio] 1.37.0: trouble with multiple timers and serial line port

               timer1_.cancel(); // Q: Is this necessary here?                timer1_.expires_from_now(boost::posix_time::milliseconds(1000));                timer1_.async_wait(bind(MemFun1, this, counter));

I can't understand why you want to cancel the timer here. Anyway, you'd better post some minimal code that compiles and runs (it shouldn't be classes with ports etc., just main(), timers and plain function handlers).