No it doesn't. The process I've been through below:
-Yesterday, I hadn't got to the bottom of it, and it was seemingly random, was googling the issue and somebody had suggested flicking the switch you mention. It has been off since yesterday and it's clicking pre and post switching it off.
-Today, heard it a few times, then went through a process of testing without speakers plugged in, then without coax, then without inputs and somewhere in that process, put two and two together and realised it was when I was using my Sky Remote. Can now reproduce the issue on demand, however to reproduce it you need to give it a few minutes in between.
All this time, no lights, no hum from the speakers or any other indication that it is doing anything, other than clicking to the Sky remote!
Must be some kind of factory IR code or sensitivity to IR, but I would have hoped that when you press the button on the front to turn it off, it was drawing no current! The supplied remote control does absolutely nothing when off on the front panel so it is extremely odd that the Sky Remote has this affect!
Thanks for your reply