When you say "board," are you referring to the motherboard (ASUS P5L-MX) or the video card (PNY XLR8 8800GT)? Also, I found some more information which supports what you say (I can't send audio out of the video card through HDMI), but I'd like a final confirmation. I've learned that in the video card world, ATI and nVidia do things differently when it comes to sound in that ATI processes sound through the GPU, so sending sound through the video card is as simple as converting the DVI output to HDMI through a converter. For a nVidia card, you need to connect the S/PDIF out on the MB (or sound card) to the S/PDIF on the video card; and <I>only</I> if your video card supports this (has a S/PDIF in).
Through a search on newegg,
http://www.newegg.com/Product/Produc...82E16814500006 is the only 8800GT that says it outputs to HDMI (with audio); my video card does not show that sound is possible (
http://www.newegg.com/Product/Produc...k=pny%2b8800gt ).
To summarize, my MB has a S/PDIF out, but my video card does not have a S/PDIF in, forcing me to run a separate audio cable. Would you agree with this assessment?