In an attempt to help out another MacRumors user with a different problem, I moved the Finder preferences file to the desktop, then logged out and back in. When that did not achieve what I wanted, I put it back and did the same thing, only before I could log in again, my mouse cursor froze! I could still click on the Sleep button, which the frozen cursor happened to be over, but I couldn't move the cursor to log back in again (this has happened before). I was forced to hard-restart the Mac - after that, the problem did not recur. Any ideas as to what was going on?