Comment 64 for bug 1236965

> since you have Headphone, Line Out and Speaker , should there be three ports instead of two ?

It's a known issue. I've added a Line Out profile upstream, it's not yet in Ubuntu. http://cgit.freedesktop.org/pulseaudio/pulseaudio/commit/src/modules/alsa/mixer/paths/analog-output-lineout.conf?id=ecf3ab2b5788c85c237eeb6429bd1d525b9ac0cc