Yeah, but mine does it ALL the time. It's not that much of an issue, I guess, but I feel pretty silly sitting at a stop light with my engine racing at 3000rpms. And it can't be good for my gas mileage.

Also, it idles that high even when I know that the throttle is fully closed - I can visually see that the throttle arm is up against the stop screw. So there must be something else that's gone screwy and is supplying the extra air to make the engine race. But what???