Just started playing Civ V. I was producing a warrior in one of my cities when I discovered metal casting (which makes warriors obsolete). A few turns later, when my warrior should have been produced, I got zilch. No warrior. No money to compensate for lost production time (like you'd get when producing a wonder that another civ produces first). Has anyone else noticed this? I guess it would be slightly less irritating if you at least got a message that you were producing an obsolete unit after discovering new research, but I sure didn't see any notification.