Thanks jaquith, i'll try your driver link.
about the headers,... i'm not sure which headers you mean but In the bios, it's set to HD audio.
My speaker system is a logitech with 7 speakers with 3 inputs...lime, black and orange, so i've connected them to their output jacks on the mobo, i.e. lime, black and orange. I think they correspond to L-R front, L-R rear and Center Sub (the speaker outputs).