ECF -Sorry for the late reply, but it takes a while for me to unhook everything to root out this problem.
To answer your questions yes they support 5.1 and are 5.1 if I use coax. On the receiver i can see the incoming signal format - anything over hdmi shows incoming as two channels. I tried different sources (live tv with 5.1, recorded tv with 5.1, ripped dvd) etc... and still no 5.1 over HDMI.