Keyboard backlight flickering in snow leopard

i have 2011 mbp , have 2 partitions on lion , 1 snow leopard. keyboard backlight on lion works fine on snow leopard can't turn down or keys downloaded app , no matter have set way off or way on still randomly flicker. ideas why?

 

what app have installed?
have tried uninstalling it? happen in another, temporarily created, user account?

 

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