I have my headphones plugged in the front of my pc and my usb speakers in the line out jack at the back.
If I switch
(with pavucontrol or the System Settings module)
to Line Out, the sound correctly comes out through the speakers;
If I switch to Headset ("auriculares" in my system), however,
the sound comes out of both the speakers and the headset.
Is this a bug or normal behaviour?

Thanks.

SOLVED:
I solved it with a not too pretty workaround with easytroke and amixer commands.