2011-10-09 10:26:01 [SEVERE] Could not pass event BLOCK_PISTON_EXTEND to WorldGuard
java.lang.ClassCastException: org.bukkit.material.MaterialData cannot be cast to org.bukkit.material.PistonBaseMaterial
	at org.bukkit.event.block.BlockPistonEvent.getDirection(BlockPistonEvent.java:41)
	at org.bukkit.event.block.BlockPistonExtendEvent.getBlocks(BlockPistonExtendEvent.java:37)
	at com.sk89q.worldguard.bukkit.WorldGuardBlockListener.onBlockPistonExtend(WorldGuardBlockListener.java:838)
	at org.bukkit.plugin.java.JavaPluginLoader$46.execute(JavaPluginLoader.java:561)
	at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:58)
	at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:339)
	at net.minecraft.server.BlockPiston.g(BlockPiston.java:70)
	at net.minecraft.server.BlockPiston.doPhysics(BlockPiston.java:47)
	at net.minecraft.server.World.k(World.java:488)
	at net.minecraft.server.World.applyPhysics(World.java:463)
	at net.minecraft.server.World.update(World.java:431)
	at net.minecraft.server.World.setTypeIdAndData(World.java:415)
	at net.minecraft.server.BlockDiode.a(SourceFile:67)
	at net.minecraft.server.World.a(World.java:2143)
	at net.minecraft.server.World.doTick(World.java:1637)
	at net.minecraft.server.MinecraftServer.h(MinecraftServer.java:461)
	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:374)
	at net.minecraft.server.ThreadServerApplication.run(SourceFile:417)
2011-10-09 10:26:01 [SEVERE] Could not pass event BLOCK_PISTON_EXTEND to WorldGuard
java.lang.ClassCastException: org.bukkit.material.MaterialData cannot be cast to org.bukkit.material.PistonBaseMaterial
	at org.bukkit.event.block.BlockPistonEvent.getDirection(BlockPistonEvent.java:41)