yep, as Glider said, not uncommon. I have an '06 E.G.C., fuel gauge fogs as soon as I pull it out of the garage in the morning and it hits the humid air. Thought of a new gasket (or something) myself, but after talking to several mechanics and parts guy's they reassured me it was common, and not a problem.
Now I just consider it a dual gauge: humidity gauge when its clouded, fuel gauge when its not.