Hopper: java.lang.ArrayIndexOutOfBoundsException: -7

This is an automatically generated report based from the following crash: http://hopper.minecraft.net/crashes/minecraft/MCX-78434/

Crash:

java.lang.ArrayIndexOutOfBoundsException: -7
	at b.a(SourceFile:330)
	at b.a(SourceFile:317)
	at act.h(SourceFile:1239)
	at kd.h(SourceFile:364)

The following is the first clean report made public about this crash:

---- Minecraft Crash Report ----
// Hey, that tickles! Hehehe!

Time: 2013-09-06 00:51
Description: Exception ticking world entities

java.lang.ArrayIndexOutOfBoundsException: -7
	at b.a(SourceFile:330)
	at b.a(SourceFile:317)
	at act.h(SourceFile:1239)
	at kd.h(SourceFile:364)
	at net.minecraft.server.MinecraftServer.t(SourceFile:463)
	at net.minecraft.server.MinecraftServer.s(SourceFile:398)
	at bng.s(SourceFile:124)
	at net.minecraft.server.MinecraftServer.run(SourceFile:332)
	at hs.run(SourceFile:575)


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

-- Head --
Stacktrace:
	at b.a(SourceFile:330)
	at b.a(SourceFile:317)
	at act.h(SourceFile:1239)
	at kd.h(SourceFile:364)

-- Affected level --
Details:
	Level name: AMP BUILD
	All players: 1 total; [kg['alienlace'/155707, l='AMP BUILD', x=-191,08, y=92,89, z=252,28]]
	Chunk stats: ServerChunkCache: 606 Drop: 0
	Level seed: 8920935434681544620
	Level generator: ID 03 - amplified, ver 0. Features enabled: true
	Level generator options: 
	Level spawn location: World: (-208,64,248), Chunk: (at 0,4,8 in -13,15; contains blocks -208,0,240 to -193,255,255), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
	Level time: 40 game time, 40 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 94772 (now: false), thunder time: 139914 (now: false)
	Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: true
Stacktrace:
	at net.minecraft.server.MinecraftServer.t(SourceFile:463)
	at net.minecraft.server.MinecraftServer.s(SourceFile:398)
	at bng.s(SourceFile:124)
	at net.minecraft.server.MinecraftServer.run(SourceFile:332)
	at hs.run(SourceFile:575)

-- System Details --
Details:
	Minecraft Version: 13w36a
	Operating System: Windows XP (x86) version 5.1
	Java Version: 1.7.0_25, Oracle Corporation
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode, sharing), Oracle Corporation
	Memory: 395448 bytes (0 MB) / 518979584 bytes (494 MB) up to 518979584 bytes (494 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M
	AABB Pool Size: 6485 (363160 bytes; 0 MB) allocated, 2656 (148736 bytes; 0 MB) used
	Suspicious classes: [com.ibm.icu.text.ArabicShapingException], [gnu.trove.TIntCollection], [gnu.trove.impl.HashFunctions, PrimeFinder], [gnu.trove.impl.hash.THash, TPrimitiveHash, TIntIntHash], [gnu.trove.iterator.TIterator, TAdvancingIterator, TIntIntIterator], [gnu.trove.map.TIntIntMap], [gnu.trove.map.hash.TIntIntHashMap], [gnu.trove.procedure.TIntIntProcedure], [gnu.trove.set.TIntSet]
	IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 742 (41552 bytes; 0 MB) allocated, 436 (24416 bytes; 0 MB) used
	Player Count: 1 / 8; [kg['alienlace'/155707, l='AMP BUILD', x=-191,08, y=92,89, z=252,28]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.

You can see this full report at http://hopper.minecraft.net/crashes/minecraft/MCX-78434/8206566/