Plugin Help SilkSpawn

Hi guys i need help with spawners ...... i am useing zpermissions with silkspawners and when i am in op i can change the spawners and they stay that way... but as soon as someone breaks it it goes back to pig (default) and if they try and place it it says they don't have permission to place that i have tried all these perms.

essentials.spawner: true
essentials.spawner.cavespider: true
essentials.spawner.skeleton: true
essentials.spawner.spider: true
essentials.spawner.zombie: true
essentials.spawnmob: true
essentials.spawnmob.*: true
essentials.spawnmob.cow: true

silkspawners.place.*: true
silkspawners.place.zombie: true
silkspawners.silkdrop.*: true
silkspawners.silkdrop.cave-spider: true
silkspawners.silkdrop.cow: true
silkspawners.silkdrop.skeleton: true
silkspawners.silkdrop.spider: true
silkspawners.silkdrop.zombie: true
spawner: true
spawnmob: true
And still having troubles.....Any help would be great.