Does Realtek calls its drivers reference design, if so then I have got a right link otherwise I give up.
wait check [link=http://www.realtek.com.tw/products/products1-1.aspx?lineid=5]Codecs[/link] for your sound.
And I have another question, did you contackt the technical staff of Asrock about this problem? Before buying a new sound card, I recommend talk to the company because if its a port problem, you will get replacement of it otherwise you will end up buying a defective Mobo.