I am using Ubuntu Studio 12.10 64 bit with Gnome 3. Fn F5 & F6 have worked to make the screen darker/brighter until today. I've not done anything different with keyboard shortcuts or installed any applications. On the last restart, several programs were reported to have crashed, so I'm not sure whether that has anything to do with anything.

The "brightness and lock" section of the System Settings allows me to adjust the screen brightness using a slider in its interface, but doesn't give me any options about keyboard shortcuts.

My computer info can be found in my signature. Thoughts on what may have happened? Thanks in advance for any help!