Don't know if it will help, but it can't hurt: Get some white grease (for some strange reason auto stores, at least in my area, have stopped carrying it) at an Ace type hardware store and apply a small amount to the key before inserting it. You might have to do this several times before you see any results. If that doesn't help, let's try something else. What? I don't know right now. I will have to think about it.