I have a sudden problem in Kubuntu 7.04 using hp pavillion dv2000 and alsa

plugging in the headphones does not mute the speakers.

this used to work fine until a day or so ago. I cannot connect it with any
changes I have made but who knows?

I have tried fooling with kmix and alsamixer but so far, nothing works.

the problem is systemic, thus it makes no difference if I use kaffeine,
mplayer, etc.

the problem does not occur in Windows Vista on the same machine.

I have am googling but so far, no good.

any clues?