Both problems have been a result of improper husbandry requirements when it comes to other tankmates. First off, in Articuno's case, it was a Condylactus anemone, which do not host any fish, and most don't have the nematocystic capabilities to capture any fish of the Pomacentridae family anyway, which all have a protective coating to protect against the nematocysts of anemones, it is more evident in the Clownfish, but some Damsels also exhibit this protective coating.
Now, on to Travis's question and problem. You state you added a baby clownfish, but not which kind, but I will assume it's an Ocellaris, based on your other clown. Most likely the little one can't manage to stick up for itself for much longer, and is probably hiding out of view, of the other Clown and yourself. Try looking around the top brace of the tank, right below the water line, and towards the back of the tank. Considering it's a baby, it is most likely in the small space between a powerhead and the water surface, near the rear of the tank. I have had several do this upon entry to the tank. Good luck in finding it.
Demo