I'm a recent switcher. On a number of occasions I've seen tutorial directions for using the various "F" keys. It seems that I have to press the "fn" key, simultaneously, to get the function. For example; "expose" only works when I press the fn key and F11 key at the same time. Is this a problem with the way my keys are mapped, or is it just a known fact that one always uses the fn key in conjunction with the F key?