[mike_187]

Are sure its not the light sensor doing this. Its a cool feature of the blackberry where it adjusts the backlights based on the lighting around you.

Put your finger over the top led indicator, and if the keypad back ligth comes on in a sec or two its fine, you can turn the feature off though if you dont like it, but it does save you battery life.

In dark environments the light should be dim and bright outsude, such as sunlight so that you can see the screen.

edit: by pressing top power key you can also adjust level of backlight manually...