I have an Onkyo HT-R520 Receiver with a 1000 watt 6.1 HT. I have had it for a couple months now, and i have started noticing that the input from my laptop creates a fairly loud hum. I have tried switching inputs on the back of the receiver, they are all the same. However, my xbox and DVD player do not create any hum. I am not sure if this helps but my ipod doesnt create any hum when using the same headphone -> RCA adapter when plugged in. But it does create a hum when it is attached to the dock which is attached to the computer. It seems like when there is power applied a hum is created. However i was using the same headphone to rca adapter for months without a problem. I made sure that the laptop and receiver/sub werent on the same power strip. I am really confused as to what is causing this annoying hum. Any ideas would be greatly appreciated.