Random Crash

Minecraft Crash Report ----
// You should try our sister game, Minceraft!

Time: 4/6/13 3:05 PM
Description: Exception while updating neighbours

java.lang.ClassCastException: net.minecraft.jammy780.furniture.tiles.jfm_TileEntityWoodBlocks cannot be cast to net.minecraft.tileentity.TileEntityChest
at net.minecraft.block.BlockChest.func_71863_a(BlockChest.java:356)
at net.minecraft.world.World.func_72821_m(World.java:839)
at net.minecraft.world.World.func_72898_h(World.java:782)
at net.minecraft.world.World.func_72851_f(World.java:735)
at net.minecraft.world.World.func_72832_d(World.java:567)
at net.minecraft.world.World.func_94571_i(World.java:682)
at net.minecraft.block.Block.removeBlockByPlayer(Block.java:1625)
at net.minecraft.item.ItemInWorldManager.func_73079_d(ItemInWorldManager.java:275)
at net.minecraft.item.ItemInWorldManager.func_73084_b(ItemInWorldManager.java:308)
at net.minecraft.item.ItemInWorldManager.func_73074_a(ItemInWorldManager.java:170)
at net.minecraft.network.NetServerHandler.func_72510_a(NetServerHandler.java:491)
at net.minecraft.network.packet.Packet14BlockDig.func_73279_a(SourceFile:46)
at net.minecraft.network.MemoryConnection.func_74428_b(MemoryConnection.java:89)
at net.minecraft.network.NetServerHandler.func_72570_d(NetServerHandler.java:134)
at net.minecraft.network.NetworkListenThread.func_71747_b(NetworkListenThread.java:53)
at net.minecraft.server.integrated.IntegratedServerListenThread.func_71747_b(IntegratedServerListenThread.java:109)
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:674)
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:570)
at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:127)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:468)
at net.minecraft.server.ThreadMinecraftServer.run(SourceFile:573)

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

– Head –
Stacktrace:
at net.minecraft.block.BlockChest.func_71863_a(BlockChest.java:356)

– Block being updated –
Details:
Source block type: ID #4095 (tile.woodBlocks // net.minecraft.jammy780.furniture.blocks.wood.jfm_WoodBlocksOne)
Block type: ID #54 (tile.chest // net.minecraft.block.BlockChest)
Block data value: 2 / 0x2 / 0b0010
Block location: World: (24,63,470), Chunk: (at 8,3,6 in 1,29; contains blocks 16,0,464 to 31,255,479), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
Stacktrace:
at net.minecraft.world.World.func_72821_m(World.java:839)
at net.minecraft.world.World.func_72898_h(World.java:782)
at net.minecraft.world.World.func_72851_f(World.java:735)
at net.minecraft.world.World.func_72832_d(World.java:567)
at net.minecraft.world.World.func_94571_i(World.java:682)
at net.minecraft.block.Block.removeBlockByPlayer(Block.java:1625)
at net.minecraft.item.ItemInWorldManager.func_73079_d(ItemInWorldManager.java:275)
at net.minecraft.item.ItemInWorldManager.func_73084_b(ItemInWorldManager.java:308)
at net.minecraft.item.ItemInWorldManager.func_73074_a(ItemInWorldManager.java:170)
at net.minecraft.network.NetServerHandler.func_72510_a(NetServerHandler.java:491)
at net.minecraft.network.packet.Packet14BlockDig.func_73279_a(SourceFile:46)
at net.minecraft.network.MemoryConnection.func_74428_b(MemoryConnection.java:89)
at net.minecraft.network.NetServerHandler.func_72570_d(NetServerHandler.java:134)
at net.minecraft.network.NetworkListenThread.func_71747_b(NetworkListenThread.java:53)
at net.minecraft.server.integrated.IntegratedServerListenThread.func_71747_b(IntegratedServerListenThread.java:109)
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:674)
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:570)
at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:127)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:468)
at net.minecraft.server.ThreadMinecraftServer.run(SourceFile:573)

– System Details –
Details:
Minecraft Version: 1.5.1
Operating System: Windows 7 (x86) version 6.1
Java Version: 1.7.0_17, Oracle Corporation
Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
Memory: 309583384 bytes (295 MB) / 519110656 bytes (495 MB) up to 1037959168 bytes (989 MB)
JVM Flags: 2 total; -Xms512m -Xmx1024m
AABB Pool Size: 1689 (94584 bytes; 0 MB) allocated, 1384 (77504 bytes; 0 MB) used
Suspicious classes: FML and Forge are installed
IntCache: cache: 0, tcache: 0, allocated: 1, tallocated: 71
FML: MCP v7.44 FML v5.1.8.611 Minecraft Forge 7.7.1.611 8 mods loaded, 8 mods active
mcp [Minecraft Coder Pack] (minecraft.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
FML [Forge Mod Loader] (coremods) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
Forge [Minecraft Forge] (coremods) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
GuiAPI [GuiAPI] (GuiAPI-0.15.4-1.5.1.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
jammyfurniture [Jammy Furniture Mod] (1.5.1_Jammy_Furniture_Mod_V4.3.zip) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
CustomSpawner [DrZhark's CustomSpawner] (CustomMobSpawner 1.12.2.zip) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
MoCreatures [DrZhark's Mo'Creatures Mod] (DrZharks MoCreatures Mod v5.0.4.zip) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
Damoniy [The Ether] (Ether1.5.1 V1.1.9.zip) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
Profiler Position: N/A (disabled)
Vec3 Pool Size: 2839 (158984 bytes; 0 MB) allocated, 2523 (141288 bytes; 0 MB) used
Player Count: 1 / 8; [EntityPlayerMP['Bcdragon7'/107, l='New World', x=25.02, y=63.00, z=469.70]]
Type: Integrated Server (map_client.txt)
Is Modded: Definitely; Client brand changed to 'forge,fml'