While using my Galaxy Nexus at night in the dark, I started experiencing issues where the screen would flash for a moment to what felt like full brightness when I tap on certain buttons. It seems inconsistent, but frequent. I've had it happen when pressing the back button in various apps, or switching to different apps in the application switcher. It's bright enough to say that it kind of hurts my eyes.
It also seems like certain screens get locked into full brightness. One example is the main timeline screen of the official Twitter app.
I have Automatic Brightness turned off, and the brightness slider at the lowest setting.
Any ideas as to what causes this? Is there some setting I'm missing?