Its just stiff thats all, it will go away with wear. I really don't think you have anything to worry about but if you are concerned just give Apple a quick call and explain the situation. Im sure they will be able to give you some piece of mind and closure. Please don't talk about changing a keyboard on a mac laptop, I had hell with the Powerbook G4 and that wasn't even fixed in like the new keyboards, I got so annoyed I sold it on LOL.