For those who have been following my problem of having no sound coming out of my 5.1 surround system (digital co-ax from Comcast 6200 stb to co-ax in on receiver), I finally figured it out. this is after reprograming the receiver i/o ports a few times as I was sure this was the problem, talking with Comcast a couple of times, reprograming the cable box, ext... I'd guess about 4-5 hours were spent either tinkering with, or thinking about, how to solve this problem.
I decided at 11:30 last night it was finally time to go behind the A/V tower and start unhooking cables to see if I messed up here somehow. I was certain I didn't but you never know. This is no easy task as I have wired the whole house for A/V, remote controls, telephone, computer, etc... and there are well over 100 terminations back there. I get to the cable in question and start to unscrew it (it is a digital coax plugged into an f-style adaptor that then screws into a co-ax terminal). I notice that cable isn't unscrewing like it should and next thing you know, the cable pulls right out of the termination. Knowing that this isn't a good thing, I replace the cable and as soon as it touches the input - instant sound.
Go figure -
Maybe that one company that pistonsfan mentioned in a previous post has a multi-thousand $ cable I can buy to not have this happen again.