Everytime i boot my Mac up, i'm getting a keyboard setup wizard telling me to press the key on the right hand side of the left shift key to set up my keyboard. However, when i do this (Mac Mini by the way) it says 'you have pressed a key on your build-in keyboard. Please press the keys on your external keyboard' I only have an external keyboard though? The Apple pro one, and that's the only thing, other than my mouse, that's connected to the PC? Any ideas?