Chestshop problem

2013-07-02 19:21:55 [SEVERE] Error occurred while enabling ChestShop v3.50-t0054 (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.Acrobot.ChestShop.Metrics.start(Metrics.java:231)
    at com.Acrobot.ChestShop.ChestShop.startStatistics(ChestShop.java:242)
    at com.Acrobot.ChestShop.ChestShop.onEnable(ChestShop.java:116)
    at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:217)
    at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:365)
    at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:381)
    at org.bukkit.craftbukkit.CraftServer.loadPlugin(CraftServer.java:265)
    at org.bukkit.craftbukkit.CraftServer.enablePlugins(CraftServer.java:247)
    at net.minecraft.server.MinecraftServer.i(MinecraftServer.java:296)
    at net.minecraft.server.MinecraftServer.d(MinecraftServer.java:275)
    at net.minecraft.server.MinecraftServer.a(MinecraftServer.java:225)
    at net.minecraft.server.DedicatedServer.init(DedicatedServer.java:140)
    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:378)
    at net.minecraft.server.ThreadServerApplication.run(SourceFile:539)