Screen dims using compiz cub

[POWMS]

I have enabled compiz on my mum's 64 bit Ubuntu desktop. It works well, but the screen dims significantly once I click the mouse button to rotate the cube. Releasing the mouse button brings the screen brightness back to normal. Is there a setting that controls the screen brightness whilst rotating the cube?
Thanks.

[ajgreeny]

Install compizconfig-settings-manager if it is not already installed, then go to General Options ->Display settings tab and remove the selection from "Lighting".

That should do it.

[POWMS]

Thanks aj, that did the trick.