Power saving: screen gets darker unwanted

[launcspad]

Something is wrong with the power saving function: it fades the screen and it gets darker when using the Compaq nx6310 laptop with battery. I switched off this function in the power saving management. But I think, this module causes the bug. I barely can start it (System->Preferences->Power saving) when clicking on its icon. It takes a while when its window popups after clicking on it. And once I checked an option to let be dark the screen, it suddendly became light. Unfortunately this happened only once, I couldn't reproduce it, but the screen still gets dark, and then after a while light again. Intrepid (8.10), everything is up-to-date.

[launcspad (weblev-deactivatedaccount)]

Working with power supply this bug won't appear.

[Tim McNamara (tim-clicks)]

Hi launcspad,

I don't think this is a bug. Power saving is designed to darken the screen, in order to save the battery.

See the attachment for the button you need to click to stop.

Hope this helps, Tim.

[launcspad (weblev-deactivatedaccount)]

The button was unselected. (I'm not a newcomer.)

And the way, the screen was darken, was not the same like selecting this option. It has got dark slowly, and after a while it was light again.
This happened only when I used battery, the bug does not appear using power cable. After a reboot the screen starts light, that's why I think, this is not a hardware error.
Does the brightness of the screen have a variable to follow up its state?