Citizens plugin is not working.

Hello. I am running a 1.6.2 server i have the latest bukkit version and i recently downloaded the plugin "Citizens" ( i have the VAULT also ) But when i get in the server and i try out the commands ( /npc create BOB ) and i press enter nothing pops up in chat, and i don't get any error messages in the server console or in-game
Sorry for my bad english
Thank you.