I have a Powerbook G4, which is probably about 8 months old now. I've noticed that ever since I bought it the tiny little grey rubber lumps in the bottom corners, which keep the lid from banging on the main body of the computer, have been disappearing inside the case. Recently I've noticed that they don't even stick out anymore, and have been pushed completely inside the case, even though I've done nothing out of the ordinary which should cause this. Just a minute ago, I poked my finger nail in the thin hole which has been left, and a bit of the rubber came out on my fingernail and has the consistancy of putty, almost. Has the rubber deteriorated? Is this normal? I'm somewhat concerned!