Hello, I've just purchased a 7.1 surround sound system and was told to connect my DVD player to the receiver using Optical Cable link for sound. I have video going to the Tv via Component cables. I am not able to get any sound. It was somewhat difficult to push the optical cable in to the DVD optical input. I am afraid I may have damaged the cable. Whenever I pull cable out, leaving one end still plugged, I do see a red beam of light on the one end. If I repeat this process with the other end, then I do not see a beam of light.(Broken?) Also, there were two "bubble" like protectors on the ends of cable, are these supposed to be taken out prior to hook up? Because they are not longer there. Please help, total newbie!!