I'm also wondering if this is perhaps a Windows conflict. Is this a function of the Realtek HD Audio driver? I am using the latest one recommended by Asus for this laptop. For the NVidia driver it includes HDMI jack support, and then I can deliver audio to my receiver over the HDMI cable. For this reason, the HDMI cable will not transmit audio. In playback devices the Realtek Digital Output only shows support for the 'optical jack' and there is no 'HDMI jack' available.
