SI error

2012-11-18 15:57:38 [SEVERE] Could not pass event InventoryClickEvent to StackableItems v0.9
org.bukkit.event.EventException
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:341)
	at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62)
	at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:477)
	at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:462)
	at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:1145)
	at net.minecraft.server.Packet102WindowClick.handle(SourceFile:31)
	at net.minecraft.server.NetworkManager.b(NetworkManager.java:290)
	at net.minecraft.server.NetServerHandler.d(NetServerHandler.java:112)
	at net.minecraft.server.ServerConnection.b(SourceFile:39)
	at net.minecraft.server.DedicatedServerConnection.b(SourceFile:30)
	at net.minecraft.server.MinecraftServer.r(MinecraftServer.java:595)
	at net.minecraft.server.DedicatedServer.r(DedicatedServer.java:222)
	at net.minecraft.server.MinecraftServer.q(MinecraftServer.java:493)
	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:426)
	at net.minecraft.server.ThreadServerApplication.run(SourceFile:856)
Caused by: java.lang.ArrayIndexOutOfBoundsException