Recently my backlight screen stopped working. Not only that, but the volume keys, backlight keys, and dim light keys aren't working either. Also, if i try to restart, shut down or sleep via the apple in the top left corner, that doesn't work either. However, if I close my macbook it will go to sleep. Sooooo, some keys and functons work, but others dont? I mean I can still get online, and do most all functions as far as I can see. I have MAC OSX-leopard. How do I fix this? Also, I had backlit problems before, but Apple fixed them (this was like 2 years ago when I first bought my mac). Maybe there's a virus?