It worked this morning; now it doesn't work. All that I did in the meantime was create a new account, with parental controls, but smcFanControl was in the list of allowed programs. And why should that account interfere with mine anyway?? It's up there in my taskbar-at-the-top thing (whatever it's called, I switched from a PC so I don't know the vocabulary) and it's showing the RPM and the temperatures just fine, but when I move the sliders nothing happens. They just stay there but the RPM doesn't change. Weird.