I just bought an officially refurbished June 2009 13" MacBook Pro, and my hard drive (a standard low-end 5400RPM 180GB hard drive) emits a persistent (if not irritating) click or rattle. The noise continues from boot to power off. The computer shows no signs of hard drive issues... even running intensive applications, I haven't yet received a spinning "beach ball" cursor or anything. The hard drive seems perfectly reliable, except for this rattle. I apologize for the off-site link, but here is a sample of the rattle from my iPhone's Voice Memos app. There's some background noise (family members, if you listen hard enough) but the rattle is very audible. Should I be worried? Should I contact Apple?