I have the late fall 2010 27" model and it's running extremely slow at start-up. I don't have anything booting up at start up and the memory usage seems to be fine. It's sluggish in the first 10 minutes of booting. Finder occasionally freezes and right clicking to 'get info' takes up to 30 seconds. Firefox lags when switching tabs and minimizing. After the first 10 minutes, the iMac seems to normalize and runs fine. Any app or utility that may help eliminate this sluggishness?