It's a little difficult to understand what you're doing. When you say "viewing TV", do you mean in MC?
madVR playing something on its own isn't normal. Maybe another media player is calling it?
Under Tools/Options/General/Behavior, you have some options that might make a difference.
Sorry thought I had made it clear that I wasn't using MC to watch TV, but watching externally via SKY. Similarly I should have clarified that I am using a Harmony remote with 2 activities set-up (1 to watch TV and the other to switch to my PC, I'm sure you are familiar with the line of remote's and their various functions that you don't need a resume from me of how they operate).
After playing around a little - I also edited my post to advise that a change in the options menu to 'clear now playing on exit' seemed to have resolved the issue of madvr playing covertly.
However now when I switch from one activity to the pc, or when opening directly into the pc from an off state (again using the harmony) the Warning message 'there is nothing to play' pops up. Hope this makes it clearer.
Thanks to you both for assisting.