CR b99 create error

2013-03-02 18:46:53 [INFO] knutremi issued server command: /cr create
2013-03-02 18:46:53 [SEVERE] null
org.bukkit.command.CommandException: Unhandled exception executing command 'cr' in plugin ChestRestock v2.3.1-SNAPSHOT-b99
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46)
	at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:186)
	at org.bukkit.craftbukkit.v1_4_R1.CraftServer.dispatchCommand(CraftServer.java:514)
	at net.minecraft.server.v1_4_R1.PlayerConnection.handleCommand(PlayerConnection.java:980)
	at net.minecraft.server.v1_4_R1.PlayerConnection.chat(PlayerConnection.java:898)
	at net.minecraft.server.v1_4_R1.PlayerConnection.a(PlayerConnection.java:853)
	at net.minecraft.server.v1_4_R1.Packet3Chat.handle(Packet3Chat.java:44)
	at net.minecraft.server.v1_4_R1.NetworkManager.b(NetworkManager.java:290)
	at net.minecraft.server.v1_4_R1.PlayerConnection.d(PlayerConnection.java:113)
	at net.minecraft.server.v1_4_R1.ServerConnection.b(SourceFile:39)
	at net.minecraft.server.v1_4_R1.DedicatedServerConnection.b(SourceFile:30)
	at net.minecraft.server.v1_4_R1.MinecraftServer.r(MinecraftServer.java:598)
	at net.minecraft.server.v1_4_R1.DedicatedServer.r(DedicatedServer.java:224)
	at net.minecraft.server.v1_4_R1.MinecraftServer.q(MinecraftServer.java:494)
	at net.minecraft.server.v1_4_R1.MinecraftServer.run(MinecraftServer.java:427)
	at net.minecraft.server.v1_4_R1.ThreadServerApplication.run(SourceFile:849)
Caused by: java.lang.IllegalArgumentException: Cannot copy null stack
	at org.apache.commons.lang.Validate.notNull(Validate.java:203)
	at org.bukkit.inventory.ItemStack.<init>(ItemStack.java:120)
	at com.dumptruckman.chestrestock.DefaultCRChest.update(DefaultCRChest.java:113)
	at com.dumptruckman.chestrestock.DefaultChestManager.createChest(DefaultChestManager.java:205)
	at com.dumptruckman.chestrestock.command.CreateCommand.runCommand(CreateCommand.java:33)
	at com.dumptruckman.chestrestock.command.TargetedChestRestockCommand.runCommand(TargetedChestRestockCommand.java:36)
	at com.dumptruckman.chestrestock.pluginbase.util.commandhandler.CommandHandler.checkAndRunCommand(CommandHandler.java:234)
	at com.dumptruckman.chestrestock.pluginbase.util.commandhandler.CommandHandler.processFoundCommands(CommandHandler.java:120)
	at com.dumptruckman.chestrestock.pluginbase.util.commandhandler.CommandHandler.locateAndRunCommand(CommandHandler.java:70)
	at com.dumptruckman.chestrestock.pluginbase.util.commandhandler.CommandHandler.locateAndRunCommand(CommandHandler.java:48)
	at com.dumptruckman.chestrestock.pluginbase.plugin.AbstractBukkitPlugin.onCommand(AbstractBukkitPlugin.java:141)
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44)
	... 15 more