hello, i am somewhat new to home audio, and i have a problem with my setup. i have my computer hooked up to my suround sound reciever with a long RCA cable. when i switch sources to listen to my computer through the reciever, i get some sort of a feedback. it is pretty loud, and quite annoying. when i was playing around with my TV the other day, i disconnected the Cable line from the back of the TV and the feedback on the reciever stopped. when I plugged it back in, there was the feedback again. does anyone know what I can do to stop this? is there some kind of a filter I can put either in the cable line or the RCA to make this stop?