Do you have the rotate cube setting checked? It's two rows down and one column to the left of the desktop cube button. Also, when you hit Ctrl+Alt+Down, keep holding Ctrl+Alt and you can hit left or right to switch desktops. Once you have rotate cube enable you can middle click and hold on the desktop and move the mouse around to rotate the cube. I recommend you play with the scale effects as well. I have it set up to show all active windows when I move my mouse the the bottom left corner of the screen. I've also been playing with the animation effects lately. You can make it do some cool effects when you do things like close or minimize windows (mine go up in flames when I close them).