Bukkit

What steps will reproduce the problem?
1.Creating Enderman, Cavespiders, Silverfish, Giant, Spawner in Monsterbox
2. Ghast,
3.

What is the expected output? What do you see instead?
We are loving Monsterbox and creating a zoo.  The box is creating fine but only some mobs will spawn. The above mob  spawners do not produce anything.

What version of the product are you using?
.03

Do you have an error log of what happened?
No, nothing happens.

Please provide any additional information below.
Spawner is created and identified as desired mob spawner. We have used set command and egg method. It is 1-30 and we have updated to the recommended craftbukkit build

Sorry, I meant to say ghast, zombie and other do work.