I find this highly annoying when i am working on my Surface Pro. It's hooked up to the power supply and just for no reason while I have the brightness set to maximum, it dims and then after a few seconds or a minute or so it goes back to the maximum brightness again. Is there anything that can be done about this? Why is it even happening? I checked the power options and I have the settings so that when its connected to the power cable, it never ever dims. Yet it keeps doing it.