Use the key combination Fn and F11 to toggle the Fn lock on and off.

I only brought this up because every once in a while, my netbook gets some of its keys locked in to the secondary set of keys, which are the ones printed in blue. This results in my netbook being rendered near useless until I switch it off - unfortunately it took me some time to figure this trick, resulting in a couple of hours attempting to fix my keyboard troubles.