I'm up to Cloudius right now and have just reached the puzzle where you need to place the moon and sun orbs in the right circles and I can't figure it out. I have been trying for half an hour and I've already checked the faq, but it tells me to use the sorcerers ring on a switch which I can't even find.
I don't remember how the switch looked exactly, but are you at the second floor of the puzzle? I don't believe I had too much trouble in the puzzle when I got to it; it was probably a pretty noticeable switch. If you still don't see it, start firing that ring everywhere.