2013-02-03 18:29:38 [SEVERE] Could not pass event BlockRedstoneEvent to Lift v32
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.TimedRegisteredListener.callEvent(TimedRegisteredListener.java:35)
at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:479)
at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:464)
at net.minecraft.server.v1_4_R1.BlockButton.interact(BlockButton.java:153)
at net.minecraft.server.v1_4_R1.PlayerInteractManager.interact(PlayerInteractManager.java:390)
at net.minecraft.server.v1_4_R1.PlayerConnection.a(PlayerConnection.java:659)
at net.minecraft.server.v1_4_R1.Packet15Place.handle(SourceFile:58)
at net.minecraft.server.v1_4_R1.NetworkManager.b(NetworkManager.java:290)
at net.minecraft.server.v1_4_R1.PlayerConnection.d(PlayerConnection.java:115)
at net.minecraft.server.v1_4_R1.ServerConnection.b(SourceFile:39)
at net.minecraft.server.v1_4_R1.DedicatedServerConnection.b(SourceFile:30)
at net.minecraft.server.v1_4_R1.MinecraftServer.r(MinecraftServer.java:589)
at net.minecraft.server.v1_4_R1.DedicatedServer.r(DedicatedServer.java:224)
at net.minecraft.server.v1_4_R1.MinecraftServer.q(MinecraftServer.java:485)
at net.minecraft.server.v1_4_R1.MinecraftServer.run(MinecraftServer.java:420)
at net.minecraft.server.v1_4_R1.ThreadServerApplication.run(SourceFile:849)
Caused by: java.lang.NullPointerException

Looks like that is an error in spigot.