Ah ok...
I went to a mac store today and they took a look at it and opened it, they said the keyboard was fine there was a little space between the top layer and bottom layer of the keyboard. While the technical people were taking my laptop apart I was looking around in the show room and they had 4 normal macbooks, and three of them made the same sound so I guess it's pretty common. They said they could order a new top-case if I really wanted but they couldn't garentee (lol, my english is a bit poor) that that one would not make the same sound so I just left it the way it is since I need my macbook for some projects I am working on and just live with it.
Pls let me know if you had some luck...
Gr.
R.