Ahhh, I misunderstood your description. Your statement that, "Moved that wire to another surround (left) and it worked fine" made me think that the receiver was okay. My apologies.
Are you running two surround speakers (like in a 5.1 set up) or four surround speakers (like in a 7.1 set up)? If you are using only two surrounds, are you sure that you have them hooked up to the correct speaker terminals on the Onkyo? Not trying to be patronizing - just asking, as it's something that might be connected wrong.
Also, did you run the auto set-up on the Onkyo? If so, did you hear any sound coming from that surround speaker? If not, I recommend that you do that. I think that it should give you a warning or notice if that speaker isn't detected.