I do use comms and audio cables from stock and (because of the lenght of it) handmade by my dealer. For mains I use MIT Z-cords II and standard main leads didn't cure the problem. The most recent firmware is installed too. It's a real brainbraker I suppose.

Paul

G68ADV, G98DH, 7000, 5200, 5200HC, JVC LCD, Samsung HD cable-receiver, Gefen 4x2 HDMI switcher, MIT cables and Logitech Harmony 1000.