Killer Cories? My disappearing Neons...

Ok, on Sunday night I fed my fish and had 4 Peppered Cories and 6 Neons (plus an unnumbered quantity of Cherry Shrimp) all in a perfectly fine 29 gallon tank. Monday afternoon I did a water change and went to feed them 2 hours later and only had 4 Cories, 3 Neons and the Shrimp. I know I didn't get them in the water change - I was watching the tube for Shrimp... So I have been looking and can't find any bodies. So, today somewhere between early afternoon and now I only have 2 Neon's plus everybody else. Again, no bodies. WHERE did they go? Water parameters are all zero (Ammonia, Nitrite and Nitrate). Have my Cories cannibalized my Neons? No one has been showing any symptoms of disease or stress, although the Cories have been a little skittish, and I haven't introduced anything new. Ideas?:huh:

Nothing on the floor, plus I have a cover I've knocked the plant's around a bit and haven't found anything short of pulling everything out. The Shrimp are all on the small juvenile side. I am seeding a filter to start a QT tank to fill up the tank so there is a sponge on one intake and a cover on the other. I just can't believe they ate the bodies that fast. Is that really possible?

Agreed. I have no idea. The tank is roughly 5 months old, as mentioned earlier all water parameters check out, and from what I can observe the remaining Neons appear to be healthy, as do the Cories. Without bodies though I can't get a good look to determine anything else. I'm just completely stumped and bummed at the moment.