My M2N-SLI Deluxe motherboard has a built-in coaxial and TOSLINK S/PDIF audio out on it, but when I connect it to my 5.1 surround sound receiver it says PCM 48 and only does 2.1 audio. I have updated the SoundMax program for that audio system, but to no avail. I called ASUS technical support and the person I talked to said that I needed this, but I don't understand why, since I already have the ports on my motherboard, and that card adds them. I don't need to audio-out for each S/PDIF, but I just need 5.1 (or Dolby Digital) on the ones that I already have. And I know this is not my receiver's problem, since it works properly on my Xbox 360's TOSLINK audio cable.