Strangest thing is happening. My MacBook Pro (2.33GHz) won't automatically sleep according to the settings in System Preferences. If I go -> Sleep it will sleep. If I close the lid it will sleep. But something is preventing it from sleeping on its own. I have unplugged all usb devices and turned airport off, so it has to be something IN the computer causing it. Any ideas? It worked fine up until about a week or so ago and I haven't done anything different.