forge 1.6.4 keeps crashing my mc

hey, forge keeps crashing I open mc up, open a world and play fo like 10 seconds and then it crashes here os the latest crash report

---- Minecraft Crash Report ----

// Quite honestly, I wouldn't worry myself about that.

Time: 4/04/14 2:06 AM

Description: Reading NBT data

java.lang.ClassCastException: net.minecraft.nbt.NBTTagString cannot be cast to net.minecraft.nbt.NBTTagShort

at net.minecraft.nbt.NBTTagCompound.func_74765_d(SourceFile:120)

at net.minecraft.item.ItemStack.func_77963_c(ItemStack.java:207)

at net.minecraft.item.ItemStack.func_77949_a(ItemStack.java:105)

at net.minecraft.entity.player.InventoryPlayer.func_70443_b(InventoryPlayer.java:620)

at net.minecraft.entity.player.EntityPlayer.func_70037_a(EntityPlayer.java:950)

at net.minecraft.entity.player.EntityPlayerMP.func_70037_a(EntityPlayerMP.java:198)

at net.minecraft.entity.Entity.func_70020_e(Entity.java:1678)

at net.minecraft.server.management.ServerConfigurationManager.func_72380_a(ServerConfigurationManager.java:239)

at net.minecraft.server.management.ServerConfigurationManager.func_72355_a(ServerConfigurationManager.java:113)

at net.minecraft.server.integrated.IntegratedServerListenThread.func_71747_b(IntegratedServerListenThread.java:97)

at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:691)

at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:587)

at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:129)

at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:484)

at net.minecraft.server.ThreadMinecraftServer.run(SourceFile:583)

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

---------------------------------------------------------------------------------------

-- Corrupt NBT tag --

Details:

Tag type found: STRING

Tag type expected: SHORT

Tag name: id

Stacktrace:

at net.minecraft.nbt.NBTTagCompound.func_74765_d(SourceFile:120)

at net.minecraft.item.ItemStack.func_77963_c(ItemStack.java:207)

at net.minecraft.item.ItemStack.func_77949_a(ItemStack.java:105)

at net.minecraft.entity.player.InventoryPlayer.func_70443_b(InventoryPlayer.java:620)

at net.minecraft.entity.player.EntityPlayer.func_70037_a(EntityPlayer.java:950)

at net.minecraft.entity.player.EntityPlayerMP.func_70037_a(EntityPlayerMP.java:198)

-- Entity being loaded --

Details:

Entity Type: null (net.minecraft.entity.player.EntityPlayerMP)

Entity ID: 30

Entity Name: Skivvles

Entity's Exact location: -1497.94, 13.98, 421.29

Entity's Block location: World: (-1498,13,421), Chunk: (at 6,0,5 in -94,26; contains blocks -1504,0,416 to -1489,255,431), Region: (-3,0; contains chunks -96,0 to -65,31, blocks -1536,0,0 to -1025,255,511)

Entity's Momentum: 0.00, 0.00, 0.00

Stacktrace:

at net.minecraft.entity.Entity.func_70020_e(Entity.java:1678)

at net.minecraft.server.management.ServerConfigurationManager.func_72380_a(ServerConfigurationManager.java:239)

at net.minecraft.server.management.ServerConfigurationManager.func_72355_a(ServerConfigurationManager.java:113)

at net.minecraft.server.integrated.IntegratedServerListenThread.func_71747_b(IntegratedServerListenThread.java:97)

at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:691)

at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:587)

at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:129)

at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:484)

at net.minecraft.server.ThreadMinecraftServer.run(SourceFile:583)

-- System Details --

Details:

Minecraft Version: 1.6.4

Operating System: Windows 8 (x86) version 6.2

Java Version: 1.7.0_51, Oracle Corporation

Java VM Version: Java HotSpot Client VM (mixed mode, sharing), Oracle Corporation

Memory: 155859336 bytes (148 MB) / 368254976 bytes (351 MB) up to 518979584 bytes (494 MB)

JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M

AABB Pool Size: 471 (26376 bytes; 0 MB) allocated, 471 (26376 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 v6.4.49.965 Minecraft Forge 9.11.1.965 3 mods loaded, 3 mods active

mcp{8.09} [Minecraft Coder Pack] (minecraft.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available

FML{6.4.49.965} [Forge Mod Loader] (minecraftforge-9.11.1.965.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available

Forge{9.11.1.965} [Minecraft Forge] (minecraftforge-9.11.1.965.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available

Profiler Position: N/A (disabled)

Vec3 Pool Size: 44 (2464 bytes; 0 MB) allocated, 44 (2464 bytes; 0 MB) used

Player Count: 0 / 8; []

Type: Integrated Server (map_client.txt)

Is Modded: Definitely; Client brand changed to 'fml,forge'