10.8.1 function key issues

Since updating to 10.8.1 my function keys no longer work as they did before the upgrade. Got so frustrated I did a clean install and it's still the same. The brightness keys don't work and the volume keys don't work (volume keys now do something different). Mute key does nothing, down volume does nothing, and up volume launches dashboard. How do I get them to their original function?

Thanks