I really hate it when I find a question that has been asked over and over again on the Internet, but no one ever posts the fix/answer. So, I’m going to post this answer. I hope it helps someone.

I recently bought a small Sony home theater system. Nothing special, but enough for my small house. This system has three HDMI inputs, and one output. The output is to my Panasonic Viera television. The inputs include my PS3 and the cable DVR box. Once I got everything hooked up, I set up my Logitech Harmony 650 remote to control everything. Whenever I would hit an “activity” button, the TV and the receiver would come on, and the would switch to the proper inputs. However, as soon as would hit the volume button on the remote, or sometimes, just after a few seconds of waiting without hitting any buttons, the receiver would go into a loop of muting itself, then unmuting, a couple times a second.

The fix? Panasonic Viera TVs can communicate with Panasonic receivers via a protocol called “Viera Link”. Sony receivers don’t like the messaging from this. I turned off Viera Link, and everything now works perfeclty.