I was actually having the same problem at my house. The situation was a little different, dedicated outlet on my gear but anytime the AC kicked on or we turned on/off the lights in the room the audio from sat wood cut out for a split second. The dedicated outlet isnt for the room it is just for the rack. I thought maybe an optical cable problem, the receiver I was using only did HDMI switching so it was a great excuse to get a new receiver also. Switched to a Z11 and hooked up optical again and still had the same problem. Switched to HDMI and the problem was still there. It only went away when I added a M1500UPS and a M5100PM from panamax. I was just using an M4300. Dont really know why but thats what fixed it.