"isn't working" tells us nothing. What is the plugin not doing? Is it not loading? Are the commands not running? Is it throwing errors in console? Is it stealing all the cakes on the server?!? Have you asked yourself these questions when you found out its not working? Is the plugin being loaded? Is the plugin in the plugins folder? Is the plugin compatible with your version of CraftBukkit(or Spigot)? Did you configure the plugin correctly? Did you follow the instructions on the plugin page correctly? Have you checked the plugin page again to make sure you aren't missing anything? Have you made sure that the plugin isn't actually stealing all the cakes?
Check the server paste (http://pastebin.com/Yg8LsxAG). It is a console error, but I don't know what is happening. All I know is that votes aren't sent Plugins (Move your mouse to reveal the content) Plugins (open) Plugins (close) Plugins (21): Titlebar, GroupManager, WorldEdit, iConomy, PerWorldPlugins, Buycraft, WorldCommand, Vault, PlotMe, Votifier, Herochat, PlotMe-DefaultGenerator, WorldGuard, GAListener, Citizens, SignTP, Multiverse-Core, GriefPrevention, Multiverse-Portals, Multiverse-SignPortals, Multiverse-NetherPortals