I've noticed over the life of my MacBook that over the past 8 months or so, it usually refuses to shut down or restart at times. I click it in the context menu and nothing seems to happen. Some apps quit, some don't, then it gives an error saying that such and such application refused to quit, and thus shutdown/restart was aborted. This happens even though the application in question had quit and is no longer running. Eventually, I've manually exited every application, and nothing. Relaunching the Finder no longer works. It just quits. The menubar disappears, but the dock remains, and the system sits there doing nothing. The only way to power the computer down is to hard shutdown or pull the battery. Any ideas? It's extremely frustrating, and probably unhealthy for the computer for it to never have a proper shut down. It seemed to restart fine after the last major update I did.