Thanks for the link. Interesting read.

However, I had tried isolating the source (I unplugged the power from every component one by one and no luck.) I also unplugged the audio cable from the component to the amplifier, still no change. Only unplugging the sub got rid of it.

From reading this, the only thing I didnt try it unplugging the cable TV from the STB. Wouldnt unplugging the STB from the wall do the same thing though?