Bukkit

What steps will reproduce the problem?
1.Create npc with trait denizen
2.Make the npc vulnerable
3.Kill the npc

Getting this error:
> 11:49:25 [SEVERE] Could not pass event EntityDeathEvent to DeadMansChest v0.8
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 net.aufdemrand.denizen.npc.traits.HealthTrait.die(HealthTrait.java:209)
at net.aufdemrand.denizen.npc.traits.HealthTrait$1.run(HealthTrait.java:290)
at org.bukkit.craftbukkit.v1_5_R2.scheduler.CraftTask.run(CraftTask.java:53)
at org.bukkit.craftbukkit.v1_5_R2.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:345)
at net.minecraft.server.v1_5_R2.MinecraftServer.r(MinecraftServer.java:510)
at net.minecraft.server.v1_5_R2.DedicatedServer.r(DedicatedServer.java:225)
at net.minecraft.server.v1_5_R2.MinecraftServer.q(MinecraftServer.java:474)
at net.minecraft.server.v1_5_R2.MinecraftServer.run(MinecraftServer.java:407)
at net.minecraft.server.v1_5_R2.ThreadServerApplication.run(SourceFile:573)
Caused by: java.lang.NullPointerException
at com.wesnc.playerchestdeath.EntLis.onEntityDeath(EntLis.java:53)
at sun.reflect.GeneratedMethodAccessor361.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:425)
... 12 more

What version of the product are you using?
DeadMansChest v0.8
CB Beta build 1.5.1-R0.1