BackFromTheDead error

2013-05-05 10:29:49 [SEVERE] Could not pass event EntityDeathEvent to BackFromTheDead v0.9.4.9
org.bukkit.event.EventException
 at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:427)
 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 org.bukkit.craftbukkit.v1_5_R3.event.CraftEventFactory.callEntityDeathEvent(CraftEventFactory.java:323)
 at net.minecraft.server.v1_5_R3.EntityLiving.dropDeathLoot(EntityLiving.java:945)
 at net.minecraft.server.v1_5_R3.EntityLiving.die(EntityLiving.java:893)
 at net.minecraft.server.v1_5_R3.EntityLiving.damageEntity(EntityLiving.java:750)
 at net.minecraft.server.v1_5_R3.EntityMonster.damageEntity(EntityMonster.java:39)
 at net.minecraft.server.v1_5_R3.EntityHuman.attack(EntityHuman.java:874)
 at net.minecraft.server.v1_5_R3.PlayerConnection.a(PlayerConnection.java:1101)
 at net.minecraft.server.v1_5_R3.Packet7UseEntity.handle(SourceFile:36)
 at net.minecraft.server.v1_5_R3.NetworkManager.b(NetworkManager.java:292)
 at net.minecraft.server.v1_5_R3.PlayerConnection.d(PlayerConnection.java:109)
 at net.minecraft.server.v1_5_R3.ServerConnection.b(SourceFile:35)
 at net.minecraft.server.v1_5_R3.DedicatedServerConnection.b(SourceFile:30)
 at net.minecraft.server.v1_5_R3.MinecraftServer.r(MinecraftServer.java:581)
 at net.minecraft.server.v1_5_R3.DedicatedServer.r(DedicatedServer.java:226)
 at net.minecraft.server.v1_5_R3.MinecraftServer.q(MinecraftServer.java:477)
 at net.minecraft.server.v1_5_R3.MinecraftServer.run(MinecraftServer.java:410)
 at net.minecraft.server.v1_5_R3.ThreadServerApplication.run(SourceFile:573)
Caused by: java.lang.IllegalArgumentException: Cannot drop a Null item.
 at org.apache.commons.lang.Validate.notNull(Validate.java:203)
 at org.bukkit.craftbukkit.v1_5_R3.CraftWorld.dropItem(CraftWorld.java:295)
 at org.bukkit.craftbukkit.v1_5_R3.CraftWorld.dropItemNaturally(CraftWorld.java:313)
 at me.apollo.backfromthedead.backfromthedeadcore.CoreListener.onEntityDeath(CoreListener.java:399)
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
 at java.lang.reflect.Method.invoke(Unknown Source)
 at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:425)
 ... 20 more