I think I know where the noise is coming from. The keyboard is on a "platform" of sorts, that rests on some aluminum covers that covers the components (namely the one "embedded" stick of memory). The "platform" that the keyboard is on has some flex to it. It's not as bad as some of the other laptops that I've seen, but it's definitely there. Anyone that has taken their 700m apart to access the memory stick under the keyboard should know what I'm talking about. Some of these keyboard platforms are actually convex, meaning that it's bowed outward in the center. I think that when you press down on the keyboard hard, to where you eliminate this flex, then it rubs down, and creates the "Squeaking" noise. My first 700m that had the paint issue had a keyboard that had more of a flex than this one, and I think it made a slight squeaking noise. This one I noticed had a slight convexness, but before installing it back, I slightly bent it back to where it's nearly flat. I've never had any squeaking noise with this keyboard.
...this is just a theory of mine, so if it doesn't work for anybody else...then don't come blaming me.