Players cant place mob spawners.

Im having a problem wiht players placing spawners. I never made any specific blacklist, and mob spawners are the only item players cant place. It says they have no permission. I recently got creaturebox so I could sell different spawners, and gave players the permissions for creaturebox to place and pick up spawners. I couldnt find anywhere that mob spawners are forbidden. The plugins I have are LWC, essentials, group manager, creaturebox, showcase, falsebook, worldguard, worldedit, vault, chestshop, mob arena, nspleef, minecartmania, nocheat, multiverse. (I have a few others, but I'm absolutely sure they have nothing do with this... Such as CHDistantFarm or redstonechips.) I looked through most of the configs for either mobspawner or item id 52, but found it nowhere. Do I need a permission node for players to use these?

 

I'm also having this with a vanilla bukkit server(No plugins) i think it's a bug.

 

You can go around this by using world edit. Select the block using the wooden axe. Then use the command: //set 52
After that use essentials /mobspawner to change the mobspawner to spawn the desired mob. But you need the permissions to do this. Maybe you can do this as a service?

(I've read that you wanted to use the Creature Box etc. But I never had this problem)