Well Michael, looks like I won't have to undergo the torment of studying the Denon 3910 manual. Don't follow how the attempted d-Link update changed things, but on the original problem I note that you said you set the 3910 to "multi channel". You may have done it, but there're two player settings that are necessary to get multichannel sound from SACDs(assuming that the particular SACD isn't stereo only): an SACD setting to read the multichannel rather than the stereo track; an audio output setting to output multichannel rather than stereo. If both weren't set multi, that might explain the original stereo only output.
