it's ubuntu 9.04
original ubuntu (alsa) drivers gave me stereo output
all i tried is to install officical realtek driver but effect was far from better. by default, alsa driver was giving me standard stereo output, but after installing official realtek drivers for alc888 (for linux) not only i didn't get 5.1 surround, i have lost stereo output.
all i have done is maximum of my linux knowledge - shortly, i am a linux noob
p.s. thank you for your help in future and i'm sorry for my bad english