I have a PowerBook G4 running OS 10.5.8 that seems to have a mind of its own when it comes to the ambient light sensor for the backlit keyboard. As of this morning the machine has decided to take control of this feature, constantly showing the level of the keyboard brightness on the screen. I am unable to uncheck the box that says automatically adjust keyboard brightness in system preferences, and when I downloaded and attempted to use lab tick (3rd party software) to control the keyboard sensor it caused the keyboard to go into a spastic on/off cycle. I have tried wiping the machine with a clean install of os 10.5 but to my disappointment the issue was still there. I do not know if this is an issue with the hardware (has the ambient light sensor just finally **** out on me?) or something else. I wish I had the original restore disk to run a hard ware check but I do not, I have also already repaired the permissions in disk utility and cleared the PRAM. Thanks for any advice!!