Extra Hard Move Issue

2013-01-22 01:29:47 [SEVERE] Could not pass event WeatherChangeEvent to ExtraHardMode v2.5
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.minecraft.server.v1_4_R1.World.n(World.java:1854)
at net.minecraft.server.v1_4_R1.WorldServer.n(WorldServer.java:859)
at net.minecraft.server.v1_4_R1.World.doTick(World.java:1804)
at net.minecraft.server.v1_4_R1.WorldServer.doTick(WorldServer.java:132)
at net.minecraft.server.v1_4_R1.MinecraftServer.r(MinecraftServer.java:572)
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: n must be positive
at java.util.Random.nextInt(Random.java:300)
at me.ryanhamshire.ExtraHardMode.BlockEventHandler.onWeatherChange(BlockEventHandler.java:404)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
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