Forge 1.6.4 works with no mods installed. When I install Pixelmon 2.3.1 I receive the following crash report. Any help would be awesome. Thanks!

 

---- Minecraft Crash Report ----
// Who set us up the TNT?

Time: 10/6/13 6:24 PM
Description: Initializing game

java.lang.NoSuchMethodError: net.minecraftforge.common.EnumHelper.addToolMaterial(Ljava/lang/String;IIFFI)Lnet/minecraft/item/Item;
at pixelmon.Pixelmon.<clinit>(Pixelmon.java:60)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at cpw.mods.fml.common.FMLModContainer.constructMod(FMLModContainer.java:462)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.common.eventbus.EventHandler.handleEvent(EventHandler.java:74)
at com.google.common.eventbus.SynchronizedEventHandler.handleEvent(SynchronizedEventHandler.java:45)
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:313)
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:296)
at com.google.common.eventbus.EventBus.post(EventBus.java:267)
at cpw.mods.fml.common.LoadController.sendEventToModContainer(LoadController.java:194)
at cpw.mods.fml.common.LoadController.propogateStateMessage(LoadController.java:174)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.common.eventbus.EventHandler.handleEvent(EventHandler.java:74)
at com.google.common.eventbus.SynchronizedEventHandler.handleEvent(SynchronizedEventHandler.java:45)
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:313)
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:296)
at com.google.common.eventbus.EventBus.post(EventBus.java:267)
at cpw.mods.fml.common.LoadController.distributeStateMessage(LoadController.java:105)
at cpw.mods.fml.common.Loader.loadMods(Loader.java:510)
at cpw.mods.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:183)
at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:473)
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:808)
at net.minecraft.client.main.Main.main(SourceFile:101)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at net.minecraft.launchwrapper.Launch.launch(Launch.java:131)
at net.minecraft.launchwrapper.Launch.main(Launch.java:27)


A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

-- Head --
Stacktrace:
at pixelmon.Pixelmon.<clinit>(Pixelmon.java:60)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at cpw.mods.fml.common.FMLModContainer.constructMod(FMLModContainer.java:462)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.common.eventbus.EventHandler.handleEvent(EventHandler.java:74)
at com.google.common.eventbus.SynchronizedEventHandler.handleEvent(SynchronizedEventHandler.java:45)
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:313)
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:296)
at com.google.common.eventbus.EventBus.post(EventBus.java:267)
at cpw.mods.fml.common.LoadController.sendEventToModContainer(LoadController.java:194)
at cpw.mods.fml.common.LoadController.propogateStateMessage(LoadController.java:174)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.common.eventbus.EventHandler.handleEvent(EventHandler.java:74)
at com.google.common.eventbus.SynchronizedEventHandler.handleEvent(SynchronizedEventHandler.java:45)
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:313)
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:296)
at com.google.common.eventbus.EventBus.post(EventBus.java:267)
at cpw.mods.fml.common.LoadController.distributeStateMessage(LoadController.java:105)
at cpw.mods.fml.common.Loader.loadMods(Loader.java:510)
at cpw.mods.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:183)
at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:473)

-- Initialization --
Details:
Stacktrace:
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:808)
at net.minecraft.client.main.Main.main(SourceFile:101)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at net.minecraft.launchwrapper.Launch.launch(Launch.java:131)
at net.minecraft.launchwrapper.Launch.main(Launch.java:27)

-- System Details --
Details:
Minecraft Version: 1.6.4
Operating System: Windows Vista (amd64) version 6.0
Java Version: 1.6.0_26, Sun Microsystems Inc.
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Sun Microsystems Inc.
Memory: 305746376 bytes (291 MB) / 385351680 bytes (367 MB) up to 954466304 bytes (910 MB)
JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
Suspicious classes: FML and Forge are installed
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
FML: MCP v8.11 FML v6.4.24.920 Minecraft Forge 9.11.1.920 4 mods loaded, 4 mods active
mcp{8.09} [Minecraft Coder Pack] (minecraft.jar) Unloaded->Constructed
FML{6.4.24.920} [Forge Mod Loader] (minecraftforge-9.11.1.920.jar) Unloaded->Constructed
Forge{9.11.1.920} [Minecraft Forge] (minecraftforge-9.11.1.920.jar) Unloaded->Constructed
pixelmon{2.3.1} [Pixelmon] (Pixelmon 2.3.1.zip) Unloaded
Launched Version: 1.6.4-Forge9.11.1.920
LWJGL: 2.9.0
OpenGL: Intel Cantiga GL version 1.5.0 - Build 7.15.10.1511, Intel
Is Modded: Definitely; Client brand changed to 'fml,forge'
Type: Client (map_client.txt)
Resource Pack: Default
Current Language: English (US)
Profiler Position: N/A (disabled)
Vec3 Pool Size: ~~ERROR~~ NullPointerException: null

Seems like an issue with pixelmon calling a method that doesn't exist. Namely it doesnt return Item.

Which typically means pixelmon isn't updated to the current MC version.