I have recently bought a CM Suppressor keyboard. They keyboard is great and I'm very impressed with the build quality. I do however have an problem with the FN keys. They don't seem to work. When pressing them, the special functions are not working. Is there something specific which I need to be looking out for to fix this? I currently can't change the brightness of the keys, activate, increase or mute volume, etc. This also means that I can't engage the Win key, or assign it to one of the other keys. Any advice?