Speakers Do Not Mute with Headphones

[Noah Duffy <n.milo.duffy@gmail.com>]

I just finished loading Debian 6.0 on my brand new Lenovo SL410.  I
love this computer and so far everything seems to have worked out of
the box, however I am having one little issue:  When I plug headphone
into the computer, the main speakers do not mute.

This should be the audio card.

00:1b.0 Audio device: Intel Corporation 82801I (ICH9 Family) HD Audio
Controller (rev 03)

I've done a some searching on the Internet, but so far no luck on
fixing it for me.

Any suggestions?

Thanks,
Noah Duffy