Mob Arena Error

2012-12-19 21:15:25 [SEVERE] Error occurred while enabling MobArena v0.94.4.81 (Is it up to date?)
java.lang.NumberFormatException: For input string: "4;20"
	at java.lang.NumberFormatException.forInputString(Unknown Source)
	at java.lang.Integer.parseInt(Unknown Source)
	at java.lang.Short.parseShort(Unknown Source)
	at java.lang.Short.parseShort(Unknown Source)
	at com.garbagemule.MobArena.util.ItemParser.getData(ItemParser.java:196)
	at com.garbagemule.MobArena.util.ItemParser.withDataAndAmount(ItemParser.java:153)
	at com.garbagemule.MobArena.util.ItemParser.parseItem(ItemParser.java:125)
	at com.garbagemule.MobArena.util.ItemParser.parseItems(ItemParser.java:98)
	at com.garbagemule.MobArena.ArenaMasterImpl.loadClass(ArenaMasterImpl.java:319)
	at com.garbagemule.MobArena.ArenaMasterImpl.loadClasses(ArenaMasterImpl.java:286)
	at com.garbagemule.MobArena.ArenaMasterImpl.initialize(ArenaMasterImpl.java:242)
	at com.garbagemule.MobArena.MobArena.onEnable(MobArena.java:81)
	at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:217)
	at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:374)
	at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:381)
	at org.bukkit.craftbukkit.CraftServer.loadPlugin(CraftServer.java:270)
	at org.bukkit.craftbukkit.CraftServer.enablePlugins(CraftServer.java:252)
	at org.bukkit.craftbukkit.CraftServer.reload(CraftServer.java:579)
	at org.bukkit.Bukkit.reload(Bukkit.java:183)
	at org.bukkit.command.defaults.ReloadCommand.execute(ReloadCommand.java:23)
	at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:186)
	at org.bukkit.craftbukkit.CraftServer.dispatchCommand(CraftServer.java:502)
	at org.bukkit.craftbukkit.CraftServer.dispatchServerCommand(CraftServer.java:494)
	at net.minecraft.server.DedicatedServer.al(DedicatedServer.java:258)
	at net.minecraft.server.DedicatedServer.r(DedicatedServer.java:223)
	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)