This really doesn't make any sense...

---- Minecraft Crash Report ----
// This doesn't make any sense!

Time: 13-1-19 13:59
Description: Exception in server tick loop

java.lang.IllegalArgumentException: n must be positive
	at java.util.Random.nextInt(Unknown Source)
	at net.minecraftforge.common.ChestGenHooks.generateStacks(ChestGenHooks.java:121)
	at net.minecraft.util.WeightedRandomChestContent.generateChestContents(WeightedRandomChestContent.java:57)
	at net.minecraft.world.gen.feature.WorldGenDungeons.generate(WorldGenDungeons.java:134)
	at net.minecraft.world.gen.ChunkProviderGenerate.populate(ChunkProviderGenerate.java:571)
	at net.minecraft.world.gen.ChunkProviderServer.populate(ChunkProviderServer.java:258)
	at net.minecraft.world.chunk.Chunk.populateChunk(Chunk.java:1258)
	at net.minecraft.world.gen.ChunkProviderServer.loadChunk(ChunkProviderServer.java:153)
	at net.minecraft.server.MinecraftServer.initialWorldChunkLoad(MinecraftServer.java:310)
	at net.minecraft.server.integrated.IntegratedServer.loadAllWorlds(IntegratedServer.java:84)
	at net.minecraft.server.integrated.IntegratedServer.startServer(IntegratedServer.java:100)
	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:458)
	at net.minecraft.server.ThreadMinecraftServer.run(ThreadMinecraftServer.java:16)


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

-- System Details --
Details:
	Minecraft Version: 1.4.7
	Operating System: Windows 7 (amd64) version 6.1
	Java Version: 1.7.0_10-ea, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 572028112 bytes (545 MB) / 1056309248 bytes (1007 MB) up to 1056309248 bytes (1007 MB)
	JVM Flags: 3 total; -Xincgc -Xmx1024M -Xms1024M
	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: 3, tallocated: 63
	FML: MCP v7.26 FML v4.7.4.520 Minecraft Forge 6.6.0.497 12 mods loaded, 12 mods active
	mcp [Minecraft Coder Pack] (minecraft.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available->Available
	FML [Forge Mod Loader] (coremods) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available->Available
	Forge [Minecraft Forge] (coremods) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available->Available
	BuildCraft|Core [BuildCraft] (bin) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available->Available
	BuildCraft|Builders [BuildCraft Builders] (bin) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available->Available
	BuildCraft|Energy [BuildCraft Energy] (bin) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available->Available
	BuildCraft|Factory [BuildCraft Factory] (bin) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available->Available
	BuildCraft|Transport [Buildcraft Transport] (bin) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available->Available
	BuildCraft|Silicon [BuildCraft Silicon] (bin) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available->Available
	bedrockTools [Bedrock Tools] (bin) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available->Available
	telicraft [Telicraft] (bin) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available->Available
	telinccore [TelincCore] (bin) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available->Available
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
	Player Count: 0 / 8; []
	Type: Integrated Server (map_client.txt)
	Is Modded: Definitely; Client brand changed to 'forge,fml'