I have a mid-2009 17" MacBook Pro and am starting to hear what sounds like the actuator arm of the hard drive going back and forth. It never used to make any noise at all so I'm wondering if I have something to worry about here? I've been using Time Machine for years now so backups aren't an issue...I just want to know if I should be expecting something to go wrong. And if it's of any relevance, I shut my computer off every night and boot it up every morning. In the last week or so, I've noticed that when shut down my computer it seems to freeze up on the desktop and stop being responsive. I usually have to press and hold the power button to force the computer to turn off. If anyone can shed any light on those two concerns I'd appreciate it!