Bukkit

2012-06-23 23:43:36 [SEVERE] Error occurred while enabling GuestGuard v0.6 (Is it up to date?)
org.bukkit.plugin.IllegalPluginAccessException: Unable to find handler list for event org.bukkit.event.player.PlayerEvent
        at org.bukkit.plugin.SimplePluginManager.getRegistrationClass(SimplePluginManager.java:552)
        at org.bukkit.plugin.SimplePluginManager.getRegistrationClass(SimplePluginManager.java:550)
        at org.bukkit.plugin.SimplePluginManager.registerEvents(SimplePluginManager.java:496)
        at us.lupusbukkit.GuestGuard.GuestGuard.onEnable(GuestGuard.java:30)
        at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:215)
        at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:337)
        at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:386)
        at org.bukkit.craftbukkit.CraftServer.loadPlugin(CraftServer.java:262)
        at org.bukkit.craftbukkit.CraftServer.enablePlugins(CraftServer.java:244)
        at net.minecraft.server.MinecraftServer.t(MinecraftServer.java:390)
        at net.minecraft.server.MinecraftServer.a(MinecraftServer.java:377)
        at net.minecraft.server.MinecraftServer.init(MinecraftServer.java:205)
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:441)
        at net.minecraft.server.ThreadServerApplication.run(SourceFile:492)