General Illumination turning off in Window

[m2tts]

I have updated to 4.3.1 and am having an issue with the working window. When I open a previously saved bip file and have self shadows and global illumination turned on, everything is fine till after I've done my first rendering. Then if I move the camera a little, or hide and show a part again, it's as if I had turned global illumination off, though I haven't, and it's still toggled on in the settings tab. Today this does not affect the rendering, though yesterday it was. I have not changed anything about the material either.