Hi again,
Sometimes when I move my systems around, the sound only comes out of one speaker. I have to twist/spin the mini-jack around in the port to get the sound to come out of both speakers. Sometimes I have to play with the speaker volume control knob too.
Have you tried any of the other sound ports? You're using the green one, right?
Have you tried a different set of working speakers on your board? If those don't work, your motherboard may be at fault.
My friend is using that same motherboard and said the on-board sound is pretty good. He never mentioned any problems with the sound ports though.
Cricket