Essentials - Nether Error

2011-02-07 02:19:18 [INFO] Starting minecraft server version Beta 1.2_01
2011-02-07 02:19:18 [INFO] Loading properties
2011-02-07 02:19:18 [INFO] Starting Minecraft server on *:25565
2011-02-07 02:19:18 [WARNING] **** SERVER IS RUNNING IN OFFLINE/INSECURE MODE!
2011-02-07 02:19:18 [WARNING] The server will make no attempt to authenticate us
ernames. Beware.
2011-02-07 02:19:18 [WARNING] While this makes the game possible to play without
 internet access, it also opens up the ability for hackers to connect with any u
sername they choose.
2011-02-07 02:19:18 [WARNING] To change this, set "online-mode" to "true" in the
 server.settings file.
2011-02-07 02:19:18 [INFO] This server is running Craftbukkit version git-Bukkit
-0.0.0-333-g2fe5517-b256 (MC: 1.2_01)
2011-02-07 02:19:18 [INFO] Preparing level "world3"
2011-02-07 02:19:18 [INFO] Preparing start region
2011-02-07 02:19:19 [INFO] Preparing spawn area: 0%
2011-02-07 02:19:21 [INFO] Preparing spawn area: 3%
2011-02-07 02:19:22 [INFO] Preparing spawn area: 4%
2011-02-07 02:19:23 [INFO] Preparing spawn area: 12%
2011-02-07 02:19:24 [INFO] Preparing spawn area: 16%
2011-02-07 02:19:25 [INFO] Preparing spawn area: 28%
2011-02-07 02:19:26 [INFO] Preparing spawn area: 32%
2011-02-07 02:19:27 [INFO] Preparing spawn area: 40%
2011-02-07 02:19:28 [INFO] Preparing spawn area: 52%
2011-02-07 02:19:29 [INFO] Preparing spawn area: 61%
2011-02-07 02:19:30 [INFO] Preparing spawn area: 65%
2011-02-07 02:19:31 [INFO] Preparing spawn area: 77%
2011-02-07 02:19:32 [INFO] Preparing spawn area: 77%
2011-02-07 02:19:33 [INFO] Preparing spawn area: 89%
2011-02-07 02:19:34 [INFO] Preparing spawn area: 97%
2011-02-07 02:19:35 [INFO] [iChat] version [1.5] (Maria Holic) loaded
2011-02-07 02:19:35 [INFO] [Permissions] version [2.0] (Handler) loaded
2011-02-07 02:19:36 [INFO] WorldEdit 3.2.2 loaded.
2011-02-07 02:19:36 [INFO] WorldEdit: Permissions plugin detected! Using Permiss
ions plugin for permissions.
2011-02-07 02:19:36 [INFO] WorldGuard 3.2.2 loaded.
2011-02-07 02:19:36 [INFO] WorldGuard: Permissions plugin detected! Using Permis
sions plugin for permissions.
2011-02-07 02:19:36 [INFO] WorldGuard: Single session is enforced.
2011-02-07 02:19:36 [INFO] WorldGuard: TNT ignition is PERMITTED.
2011-02-07 02:19:36 [INFO] WorldGuard: Lighters are PERMITTED.
2011-02-07 02:19:36 [INFO] WorldGuard: Lava fire is blocked.
2011-02-07 02:19:36 [INFO] WorldGuard: Fire spread is UNRESTRICTED.
Feb 7, 2011 2:19:36 AM org.bukkit.craftbukkit.CraftServer loadPlugins
SEVERE: org.bukkit.Server.getWorlds()Ljava/util/List; (Is it up to date?)
java.lang.NoSuchMethodError: org.bukkit.Server.getWorlds()Ljava/util/List;
        at org.bukkit.earth2me.essentials.Essentials.onEnable(Essentials.java:12
1)
        at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:135)
        at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader
.java:384)
        at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManage
r.java:175)
        at org.bukkit.craftbukkit.CraftServer.loadPlugin(CraftServer.java:64)
        at org.bukkit.craftbukkit.CraftServer.loadPlugins(CraftServer.java:45)
        at net.minecraft.server.MinecraftServer.e(MinecraftServer.java:156)
        at net.minecraft.server.MinecraftServer.c(MinecraftServer.java:143)
        at net.minecraft.server.MinecraftServer.d(MinecraftServer.java:104)
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:186)
        at net.minecraft.server.ThreadServerApplication.run(SourceFile:512)
2011-02-07 02:19:36 [INFO] Done! For help, type "help" or "?"
2011-02-07 02:26:30 [INFO] Ishikiwa logged in with entityid 233
Player count: 1
2011-02-07 02:26:44 [INFO] Stopping server
2011-02-07 02:26:49 [INFO] Saving chunks