SO, I have made some more effort at resolving this myself, including a new install of the game, and updating to the nvidia drivers released the other day.
Went for a flight, used my mouse to turn on the cabin lights in the tbm930, CTD
Visited my support ticekt to update it, only to find it has been resolved.
WTF.
I am beginning to understand why so many people on here are getting fed up.
Completely unusable at the moment for me.