I'm not doubting that you are having a problem. I don't know why you are having the problem, or the window heat warnings, as I don't have that happen for me in  FSX (I'll have to check to see if it happens in FSX-SE on my laptop because it installed directly into FSX-SE as if it was the FSX).

Edit. No problems in FSX-SE either. I can select OFF, and I don't get any window heater warnings.