Issue with key backlighting

I have an issue with my backlight keys in Mountain Lion. Specifically, I find that I sometimes cannot change the key backlight. When I press on the keys to increase or decrease the backlight I get an icon showing that it cannot be done. Anybody else experience this? Usually restarting the system resolves this but it is worrisome and annoying.

 

Ok, never mind, it's the light sensor preventing me from doing it. It works fine when I cover it up with my hand. One annoying issue is the fact that in windows keys always get reset to highest brightness after restating the system.