Hi, I recently purchased a Macbook Pro 15" and I started noticing a few strange sounds. I've dropped the computer in a bag case which is very protective on the carpet slightly, but I don't think that affected anything. 1) At started, there is an around 4 second sound. I was told that is the hard drive and it is normal, so is that true? 2) Sometimes when I turn the computer, like tilt it to the right or left... It makes a sound that I can't really describe. It is kind of a lamp sound... "ding". I hope you can imagine it. My old Macbook didn't do that, so is this normal?? And what is it? Thanks.