Hopper: java.lang.RuntimeException: Already decorating!!

This is an automatically generated report based from the following crash: http://hopper.minecraft.net/crashes/minecraft/MCX-14552/

Crash:

java.lang.RuntimeException: Already decorating!!
	at act.a(SourceFile:21)
	at acp.a(SourceFile:217)
	at aes.a(SourceFile:454)
	at jq.a(SourceFile:168)
	at adq.a(SourceFile:732)
	at jq.c(SourceFile:105)
	at jp.<init>(SourceFile:29)
	at jo.a(SourceFile:208)
	at jo.d(SourceFile:337)
	at hm.d(SourceFile:197)
	at jz.a(SourceFile:267)
	at et.a(SourceFile:136)
	at cm.b(SourceFile:64)
	at jz.e(SourceFile:60)

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

---- Minecraft Crash Report ----
// I blame Dinnerbone.

Time: 9.8.13 18:04
Description: Ticking memory connection

java.lang.RuntimeException: Already decorating!!
	at act.a(SourceFile:21)
	at acp.a(SourceFile:217)
	at aes.a(SourceFile:454)
	at jq.a(SourceFile:168)
	at adq.a(SourceFile:732)
	at jq.c(SourceFile:105)
	at jp.<init>(SourceFile:29)
	at jo.a(SourceFile:208)
	at jo.d(SourceFile:337)
	at hm.d(SourceFile:197)
	at jz.a(SourceFile:267)
	at et.a(SourceFile:136)
	at cm.b(SourceFile:64)
	at jz.e(SourceFile:60)
	at kc.b(SourceFile:37)
	at bkz.b(SourceFile:84)
	at net.minecraft.server.MinecraftServer.t(SourceFile:488)
	at net.minecraft.server.MinecraftServer.s(SourceFile:405)
	at bkw.s(SourceFile:124)
	at net.minecraft.server.MinecraftServer.run(SourceFile:339)
	at hh.run(SourceFile:582)


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

-- Head --
Stacktrace:
	at act.a(SourceFile:21)
	at acp.a(SourceFile:217)
	at aes.a(SourceFile:454)
	at jq.a(SourceFile:168)
	at adq.a(SourceFile:732)
	at jq.c(SourceFile:105)
	at jp.<init>(SourceFile:29)
	at jo.a(SourceFile:208)
	at jo.d(SourceFile:337)
	at hm.d(SourceFile:197)
	at jz.a(SourceFile:267)
	at et.a(SourceFile:136)
	at cm.b(SourceFile:64)
	at jz.e(SourceFile:60)

-- Ticking connection --
Details:
	Connection: jz@163adc9
Stacktrace:
	at kc.b(SourceFile:37)
	at bkz.b(SourceFile:84)
	at net.minecraft.server.MinecraftServer.t(SourceFile:488)
	at net.minecraft.server.MinecraftServer.s(SourceFile:405)
	at bkw.s(SourceFile:124)
	at net.minecraft.server.MinecraftServer.run(SourceFile:339)
	at hh.run(SourceFile:582)

-- System Details --
Details:
	Minecraft Version: 1.6.2
	Operating System: Linux (i386) version 3.2.0-4-686-pae
	Java Version: 1.6.0_26, Sun Microsystems Inc.
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode, sharing), Sun Microsystems Inc.
	Memory: 8640000 bytes (8 MB) / 518979584 bytes (494 MB) up to 518979584 bytes (494 MB)
	JVM Flags: 1 total; -Xmx512M
	AABB Pool Size: 4854 (271824 bytes; 0 MB) allocated, 4454 (249424 bytes; 0 MB) used
	Suspicious classes: No suspicious classes found.
	IntCache: cache: 0, tcache: 33, allocated: 3, tallocated: 63
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 1352 (75712 bytes; 0 MB) allocated, 1147 (64232 bytes; 0 MB) used
	Player Count: 1 / 8; [ju['vitek25'/1757555, l='Nový svět', x=1110,50, y=-469,50, z=67,50]]
	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-14552/1611263/