Hello, ever since I got my black MacBook I've had an issue with the fn key. I've reproduced it at an Apple store and also called Apple (June 5) but no solution and no feedback so far.
Here's the problem:
In some applications you can use "APPLE + FN + PAGE UP" to perform a function. The behavior on the MacBook is different depending on whether you hold down the "APPLE" key or the "FN" key first. If "FN" is pressed first, then the MacBook ignores it and the result is "APPLE + PAGE UP."
I use the FN key everyday because I'm a software developer and need to jump around code. All these years I've been pressing the FN key first, but now I'm getting used to pressing the "APPLE" key first (but at a loss of productivity).
This has been tested on 3 MacBooks -- Mine, the Apple Store's, and by calling Apple Support.