My mac mini has around 75GB of free space when restarted, but for some reason the free space drops off dramatically very quickly. I restarted last night, but this morning its already down to 60GB and I'm getting the occasional pinwheel popup. Sometimes it gets down to 20GB, it's not even usable at this point as even scrolling down a web page causes the pinwheel to popup for minutes at a time. Any idea what could be causing the massive loss of free space and slow down so quickly? It's mainly used as a web machine, I use firefox as my browser. Occasionally I do iphone development with Xcode but I haven't used xcode since it was last restarted.