Hi Koohi,
Your bios is correct, I have just been to the Gigabyte website and downloaded a copy of the motherboard manual, if you dont have this go here
http://www.gigabyte.com.tw/Support/M...l&FileID=18436
It has a very good and easy to understand explanation of the audio on this board.
I think you should have a look here first as it should be much more help to you than I can be on the other end of an internet connection. Should you still have problems or questions afterwards just write a new entry to this thread and I will get back to you.
Let me know either way it goes
Pooch