Master volume doesn't work with headphones

[Snow Mountains]

(Posted this yesterday to the multimedia list, but questions list
seems to be more appropriate. Sorry for double posting.)

Hi FreeBSD people,
I have a simple mixer question. What I can do to get Master volume
working the same way with and without headphones?
If I plug in headphones (dell i5100), master volume does nothing (even
if I set it to 0 or 100), and I must use pcm; this is not nice because
then KDE tray volume control doesn't work.
What is the cause of this and how can I change it?
Apologize if this is a stupid question.

%sysctl -a | grep snd
hw.snd.report_soft_formats: 1
hw.snd.targetirqrate: 32
hw.snd.verbose: 1
hw.snd.maxautovchans: 4
hw.snd.unit: 0
hw.snd.pcm0.buffersize: 16384

%mixer
SM Mixer vol      is currently set to  83:83
Mixer pcm      is currently set to  78:78
Mixer speaker  is currently set to  75:75
Mixer line     is currently set to  75:75
Mixer mic      is currently set to   0:0
Mixer cd       is currently set to  75:75
Mixer rec      is currently set to 100:100
Mixer igain    is currently set to 100:100
Mixer ogain    is currently set to  70:70
Mixer line1    is currently set to   0:0
Mixer phin     is currently set to   0:0
Mixer phout    is currently set to   0:0
Mixer video    is currently set to  75:75
Recording source: mic

%kldstat
Id Refs Address    Size     Name
 1   14 0xc0400000 742370   kernel
 3    2 0xc0b4e000 1af50    linux.ko
 4    1 0xc0b69000 58554    acpi.ko
 5    1 0xc3adf000 5000     snd_ich.ko
 6    1 0xc3ae4000 1c000    sound.ko
 7    1 0xc3b12000 6000     linprocfs.ko
 8    1 0xc3b22000 4000     logo_saver.ko

Thank you
SM