Bukkit

When attempting to start the server I get this...
07:55:14 [SEVERE] Error occurred while enabling StopThatLag v0.4 (Is it up to date?)
java.lang.NoSuchMethodError: org.bukkit.scheduler.BukkitScheduler.runTaskTimerAsynchronously(Lorg/bukkit/plugin/Plugin;Ljava/lang/Runnable;JJ)Lorg/bukkit/scheduler/BukkitTask;
        at com.maxpowa.stopthatlag.MetricsLite.start(MetricsLite.java:157)
        at com.maxpowa.stopthatlag.StopThatLagMain.onEnable(StopThatLagMain.java:105)
        at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:215)
        at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:337)
        at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:386)
        at org.bukkit.craftbukkit.CraftServer.loadPlugin(CraftServer.java:264)
        at org.bukkit.craftbukkit.CraftServer.enablePlugins(CraftServer.java:246)
        at net.minecraft.server.MinecraftServer.t(MinecraftServer.java:387)
        at net.minecraft.server.MinecraftServer.a(MinecraftServer.java:374)
        at net.minecraft.server.MinecraftServer.init(MinecraftServer.java:208)
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:438)
        at net.minecraft.server.ThreadServerApplication.run(SourceFile:492)

That in itself isn't an issue however I get this when running stl
07:55:48 [INFO] Removing lag-causing entities!
07:55:48 [WARNING] Unexpected exception while parsing console command
org.bukkit.command.CommandException: Unhandled exception executing command 'stl' in plugin StopThatLag v0.4
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:42)
        at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:166)
        at forge.bukkit.ForgeCommandMap.dispatch(ForgeCommandMap.java:55)
        at org.bukkit.craftbukkit.CraftServer.dispatchCommand(CraftServer.java:497)
        at org.bukkit.craftbukkit.CraftServer.dispatchServerCommand(CraftServer.java:493)
        at net.minecraft.server.MinecraftServer.b(MinecraftServer.java:625)
        at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:593)
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:467)
        at net.minecraft.server.ThreadServerApplication.run(SourceFile:492)
Caused by: java.lang.NoClassDefFoundError: org/bukkit/entity/FallingBlock
        at com.maxpowa.stopthatlag.StopThatLagMain.isLagEntity(StopThatLagMain.java:277)
        at com.maxpowa.stopthatlag.StopThatLagMain.stopLag(StopThatLagMain.java:226)
        at com.maxpowa.stopthatlag.StopThatLagMain.onCommand(StopThatLagMain.java:163)
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:40)
        ... 8 more
Caused by: java.lang.ClassNotFoundException: org.bukkit.entity.FallingBlock
        at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
        at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
        at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:41)
        at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:29)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
        ... 12 more