Go outside in good daylight and get the lens to focus on something nice and contrasty like a car number plate. Then take two steps backwards and get it to re-focus. Does it take 2 seconds to re-focus? If so, there's probably something wrong with the camera or the lens. If not, we've established that it doesn't *always* take 2 seconds, so now you need to start giving us some details about the conditions in which it *does* take 2 seconds.