I have no idea what happened. Overnight, Preview completely stopped working. When I double click a PDF, it'll bounce around a while in the dock and then the icon will stay there, though without the dot below it indicating that it should be running. When I right-click the icon, it says "Application Not Responding" and gives me the option to force quit it. I'm running Snow Leopard 10.6.1. I tried deleting the com.apple.preview... file in username/library/preferences and restarting Preview, but that did nothing. Anyone have a clue what went wrong here?