My friend has an older (I believe Rev B) MBA and it's become very, very, very sluggish. Like 10 minutes to boot sluggish. Click a window, it beachballs, opens 30 seconds later. I did a safe boot to boot faster. Checked the login items-- only ituneshelper loads at startup. Checked the activity monitor-- the CPU is NOT pegged. Only 2-3% for the activity monitor itself and nothing else. I know he'd previously taken it to the Genius Bar and they'd reinstalled Snow Leopard. He has the HDD, not SSD, so it's possible the drive is failing, although the OS is still booting, just very slowly. The only thing I can think of is to reinstall Combo Update 10.6.4, which I've read has fixed slow boots for some people. Or I could fix permissions/ run the weekly cron. Any other ideas?