ALSA AUDIO DRIVER simultaneous sound in laptop speaker and headphones

[mihai rotarescu]

Hi,
I have a Dell Vostro Laptop, core2 duo, with kubuntu 10.04 installed in 
paralel with windows 7(grub boot).
I have an issue with the sound, meaning that I plug my headphones in the 
laptop, the sound from the laptop speakers continue playing and then as result 
i get sound in headphones as well as in laptop speaker. I don't face the same 
problem when i plug the headphones when using windows 7.

I have checked on internet for solutions and somwhow i undestand that it maybe 
a problem with the audio driver...( i have checked dell driver cd i got with 
my laptop and I have the audio driver in a deb file but it is only for 32 bit)

I would appreciate any support in finding a solution for this problem, as this 
means a lot for me, as I am using kubuntu as default OS.

thanks a lot,
mihai