Light Sensor Stops Working After Sleep

I've got an old school PB G4 Alu and after the machine sleeps, the ambient light sensor seems to just shut off or something because everything works fine from a startup, backlit keyboard and screen dim. But after the machine has been put to sleep and woken, the sensor just stops working, the backlit keyboard is still functional using a program called lab tick but is not adjustable using the F8-10 keys. I would rather keep using the light sensor, so far the only way to fix it is a restart. And its kinda annoying if you know what I mean. Anyone got any ideas?