[sndvol32] should draw some channels as disabled, but doesn't

Tested on XPSP3, sndvol32 of MS against sndvol32 of ros 0.4.11-RC-34-g5e059e7
Audio driver is Realtek HD Audio.

Expected result
XPSP3 sndvol.exe draws some channels like "Front", "Rear", "Subwoofer", "Center" in disabled style.
xpsp3_sndVol.PNG
I am not aware why these have to be drawn disabled, eventually nothing is plugged there physically? I do not use those channels actually in my setup.

Observed result
All channels are erroneously drawn enabled
sndvol32_of_ros_0.4.11-RC-34-g5e059e7_runOnXPSP3.PNG