Keys on aluminium Powerbooks making sticky/squishy/squeaking sound?

[Renaud Dreyer]

I have a 15" aluminium Powerbook that is a few weeks old. The machine 
is perfect, as far as I can see, except for the keyboard. Certains keys 
(the left and down arrows, as well as occasionally the left Function 
and Control keys) make a sticky/squishy/squeaking sound when released. 
I didn't spill anything on the keyboard (this problem started with the 
machine out of the box) and compressed air doesn't do anything.

Does anyone have the same problem? Strangely enough, the noise 
disappears when the key is pressed down and kept down for a few 
seconds... but reappears a few minutes later. I'm wary of sending the 
machine to Apple for such a small problem (getting it back in possibly 
worse shape) but this noise is starting to drive me crazy. Thanks,

            Renaud