Just a note: Yesterday I installed pulseaudio. It did not help. But I can see that pulseaudio automatically changes two channels: unplugged: set Headphone to 0 and M and Speaker+LO to 100. unplugged: set Headphone to 100 and unM and Speaker+LO to 0 and M. So pulseaudio does exactly what one should expect, but it has not the effect one should expect.