I just tried the Control Panel mood changer myself -- for the first time in a couple of years, I think. I selected one of the moods and looked for how to "save changes." Nothing seemed to happen until I clicked the Reload button in my browser; then my mood (the one onscreen, that is

) changed. I selected "No mood" and clicked Reload again. The mood I'd selected earlier went away.
What happens when you try that?