Hello thd777.

I'm having a problem trying to adjust the power settings for the point light.  All appears fine before I try to assign it any animation properties because I am able to set the power value and it stays as I touch other objects on the screen.

However, once I have the point light selected, pull up the animation window, set first keyframe at frame zeo to power keyframe and set power to 100 then slide the time line arrow to the next target key frame and set the light to 0 power then set keyframe power the light reverts back to 100.  It won't accept the zero setting.