Scene overexposed when using interior lightning with CPU

[sanderhalter]

Hi everyone, I wanted to render this scene with my CPU in interior mode. It is positioned in a room with windows with a completely white HDRI on the outside. When I turn on the interior lightning (and the global illumination), the scene becomes flakey and then overexposes completely.
I was curious how it would look like with GPU mode, and then it looked just fine.
Does anyone know how to properly render this with CPU?

[djnoone]

Can you supply a work file (KSP)?