Hey Gonk, the buzz is there whether the lights are ON or OFF. The recessed lighting front and rear are both on Lutron dimmers. Should I try and run the extension cord from the projector to the same spot the receiver is plugged into? If I still get the buzzing sound, what does this prove? When I get home from work this afternoon I'm going to take the Elite upstairs to see if I can reproduce the same problems on the upstairs rig, try and rule out the receivers HDMI inputs being the problem.