This is hard to explain. Last night I did something that somehow, accidentally routed the sound from the laptop PC/J River that I use as the primary source on my main stereo system to the stereo/HT system upstairs, and it was blasting at full volume.
I know I clicked on something I didn't want to, and then tried to back track and the above was the result.
I use a Samsung Galaxy Tab2 7 with Splashtop as a remote control for the PC/J River. Both the Tab2 and PC are obviously conneted via WiFi, and so is the reciever on the stereo/HT upstairs.
Somehow the laptop PC took control of the receiver on the other system.