screen brightness changed in the wrong way

[Guest]

Hi , with kubuntu 11.10 the hardware buttons to change brightness works strange on my Toshiba Satellite.

When I press Fn+F6( wanted to make it dark), The screen gets brightened, but the graphical bar shows it was darkened.
WHen I press Fn+F7(wanted to make it brigh), the screen gets darkened, but the graphical bar shows it was brightened.

So the graphical bar show the minimum when the screen is the brightest., and it shows maximum when the screen is the darkest.

Any idea?