Bukkit

What steps will reproduce the problem?
1.Start server

What is the expected output? What do you see instead?
Unknown error

What version of the product are you using?
0.7.1 Latest verison of Biomed

This server is running CraftBukkit version git-Bukkit-1.4.7-R1.0-61-g388a299-b2703jnks (MC: 1.5.1) (Implementing API version 1.5.1-R0.1-SNAPSHOT)

Do you have an error log of what happened?
2013-03-25 05:47:14 [SEVERE] Could not pass event WorldLoadEvent to BioMed v0.7.1
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.SimplePluginManager.fireEvent(SimplePluginManager.java:477)
    at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:462)
    at org.bukkit.craftbukkit.v1_5_R2.CraftServer.createWorld(CraftServer.java:762)
    at org.bukkit.Bukkit.createWorld(Bukkit.java:156)
    at org.bukkit.WorldCreator.createWorld(WorldCreator.java:235)
    at com.onarandombox.MultiverseCore.utils.WorldManager.doLoad(WorldManager.java:409)
    at com.onarandombox.MultiverseCore.utils.WorldManager.doLoad(WorldManager.java:390)
    at com.onarandombox.MultiverseCore.utils.WorldManager.doLoad(WorldManager.java:365)
    at com.onarandombox.MultiverseCore.utils.WorldManager.loadWorlds(WorldManager.java:664)
    at com.onarandombox.MultiverseCore.MultiverseCore.onEnable(MultiverseCore.java:300)
    at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:217)
    at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:457)
    at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:381)
    at org.bukkit.craftbukkit.v1_5_R2.CraftServer.loadPlugin(CraftServer.java:282)
    at org.bukkit.craftbukkit.v1_5_R2.CraftServer.enablePlugins(CraftServer.java:264)
    at net.minecraft.server.v1_5_R2.MinecraftServer.j(MinecraftServer.java:303)
    at net.minecraft.server.v1_5_R2.MinecraftServer.e(MinecraftServer.java:282)
    at net.minecraft.server.v1_5_R2.MinecraftServer.a(MinecraftServer.java:242)
    at net.minecraft.server.v1_5_R2.DedicatedServer.init(DedicatedServer.java:150)
    at net.minecraft.server.v1_5_R2.MinecraftServer.run(MinecraftServer.java:381)
    at net.minecraft.server.v1_5_R2.ThreadServerApplication.run(SourceFile:573)
Caused by: java.lang.NoClassDefFoundError: org/bukkit/craftbukkit/v1_4_R1/block/CraftBlock
    at me.karlmarx.biomed.GlobalBlockPopulator.setBiome(GlobalBlockPopulator.java:32)
    at me.karlmarx.biomed.BioMedPlugin.initWorld(BioMedPlugin.java:80)
    at me.karlmarx.biomed.BioMedPlugin.onWorldLoad(BioMedPlugin.java:55)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:425)
    ... 22 more
Caused by: java.lang.ClassNotFoundException: org.bukkit.craftbukkit.v1_4_R1.block.CraftBlock
    at org.bukkit.plugin.java.PluginClassLoader.findClass0(PluginClassLoader.java:70)
    at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:53)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
    ... 30 more

Please provide any additional information below.

Please update for 1.5.1 I need this plugin for my skyblock world to keep it 1 biome