Received this error just now.

2012-05-24 16:32:23 [SEVERE] Could not pass event BlockPistonExtendEvent to PreciousStones
org.bukkit.event.EventException
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:303)
at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62)
at org.bukkit.plugin.TimedRegisteredListener.callEvent(TimedRegisteredListener.java:30)
at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:459)
at net.minecraft.server.BlockPiston.g(BlockPiston.java:75)
at net.minecraft.server.BlockPiston.doPhysics(BlockPiston.java:52)
at net.minecraft.server.World.k(World.java:518)
at net.minecraft.server.World.applyPhysics(World.java:496)
at net.minecraft.server.World.update(World.java:459)
at net.minecraft.server.World.setTypeIdAndData(World.java:444)
at net.minecraft.server.BlockRedstoneTorch.a(BlockRedstoneTorch.java:142)
at net.minecraft.server.World.a(World.java:2407)
at net.minecraft.server.World.doTick(World.java:1755)
at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:554)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:459)
at net.minecraft.server.ThreadServerApplication.run(SourceFile:492)
Caused by: java.lang.NullPointerException
at net.sacredlabyrinth.Phaed.PreciousStones.listeners.PSBlockListener.onBlockPistonExtend(PSBlockListener.java:1027)
at sun.reflect.GeneratedMethodAccessor186.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:301)
... 15 more
2012-05-24 16:32:24 [INFO] TormentorDragon: Teleporting TormentorDragon to Manaphy1111
2012-05-24 16:32:37 [INFO] PreciousStones version 9.1.1
2012-05-24 16:34:00 [INFO] This server is running CraftBukkit version git-Bukkit-1.2.5-R1.3-23-g97a8c0b-b2197jnks (MC: 1.2.5) (Implementing API vers
ion 1.2.5-R2.0)

fixed