Blimey, I've never encountered this before.
Are you saying that it's a bug that's uniquely related to the trackpad? Does it not do it when you use a mouse?
Oh gosh, this is so annoying. I've heard of it happening before.
The DisplayProfile app will tell you which profile is being used. I discussed it in this article: https://www.damiensymonds.net/art_vista.html
Can you find me a link to the user manual of your screen?
Are you sure your light is ok? https://www.damiensymonds.net/2012/01/light-around-your-computer.html