I just figured out something that may be baffling others. I was looking at my photography blog, Sharondipity Photography, and noticed that my label cloud was not there. PFFFFTTTTT....gone.
If you have installed the label cloud and have problems, this may be the reason why. Quotation marks. Make sure that you don't have quotation marks in any labels. If you do, go through and remove them.
Another thing. At least one of your labels have to be in more than one post. Otherwise it won't work. I don't know why. I just know that is the way it is.