Server crashes when brewing a Fire Resistance potion

When brewing a Fire Restistance potion, the server crashes.

Steps to reproduce:

• Brew a Fire resistance potion

It seems like it ouly happens on server.

Crash report:

---- Minecraft Crash Report ----
// I bet Cylons wouldn't have this problem.

Time: 26/06/13 12:01
Description: Ticking tile entity

java.lang.NullPointerException
	at arp.l(SourceFile:106)
	at arp.h(SourceFile:63)
	at abq.h(SourceFile:1268)
	at jo.h(SourceFile:364)
	at net.minecraft.server.MinecraftServer.t(SourceFile:470)
	at io.t(SourceFile:262)
	at net.minecraft.server.MinecraftServer.s(SourceFile:405)
	at net.minecraft.server.MinecraftServer.run(SourceFile:339)
	at he.run(SourceFile:582)


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

-- Head --
Stacktrace:
	at arp.l(SourceFile:106)
	at arp.h(SourceFile:63)

-- Tile entity being ticked --
Details:
	Name: Cauldron // arp
	Block type: ID #117 (tile.brewingStand // amv)
	Block data value: 7 / 0x7 / 0b0111
	Block location: World: (-711,59,1922), Chunk: (at 9,3,2 in -45,120; contains blocks -720,0,1920 to -705,255,1935), Region: (-2,3; contains chunks -64,96 to -33,127, blocks -1024,0,1536 to -513,255,2047)
	Actual block type: ID #117 (tile.brewingStand // amv)
	Actual block data value: 7 / 0x7 / 0b0111
Stacktrace:
	at abq.h(SourceFile:1268)
	at jo.h(SourceFile:364)

-- Affected level --
Details:
	Level name: world
	All players: 2 total; [jr['DofMine'/1445716, l='world', x=-708,62, y=58,00, z=1921,26], jr['TaRhKeR'/1447794, l='world', x=599,56, y=63,00, z=-590,30]]
	Chunk stats: ServerChunkCache: 5499 Drop: 0
	Level seed: -2370322192771616643
	Level generator: ID 00 - default, ver 1. Features enabled: true
	Level generator options: 
	Level spawn location: World: (252,64,-156), Chunk: (at 12,4,4 in 15,-10; contains blocks 240,0,-160 to 255,255,-145), Region: (0,-1; contains chunks 0,-32 to 31,-1, blocks 0,0,-512 to 511,255,-1)
	Level time: 433001357 game time, 5147772 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 9298 (now: false), thunder time: 19372 (now: false)
	Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: false
Stacktrace:
	at net.minecraft.server.MinecraftServer.t(SourceFile:470)
	at io.t(SourceFile:262)
	at net.minecraft.server.MinecraftServer.s(SourceFile:405)
	at net.minecraft.server.MinecraftServer.run(SourceFile:339)
	at he.run(SourceFile:582)

-- System Details --
Details:
	Minecraft Version: 1.6
	Operating System: Linux (amd64) version 3.8.13-mtxserv-version1
	Java Version: 1.7.0_03, Oracle Corporation
	Java VM Version: OpenJDK 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 447966192 bytes (427 MB) / 1092620288 bytes (1042 MB) up to 2128150528 bytes (2029 MB)
	JVM Flags: 13 total; -Xms768M -Xmx2048M -XX:MaxPermSize=128M -XX:+UseFastAccessorMethods -XX:+UseConcMarkSweepGC -XX:+UseParNewGC -XX:+CMSIncrementalMode -XX:+CMSIncrementalPacing -XX:ParallelGCThreads=4 -XX:SurvivorRatio=16 -XX:UseSSE=4 -XX:+AggressiveOpts -Xnoclassgc
	AABB Pool Size: 17604 (985824 bytes; 0 MB) allocated, 16649 (932344 bytes; 0 MB) used
	Suspicious classes: No suspicious classes found.
	IntCache: cache: 0, tcache: 0, allocated: 1, tallocated: 63
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 3393 (190008 bytes; 0 MB) allocated, 3007 (168392 bytes; 0 MB) used
	Player Count: 2 / 15; [jr['DofMine'/1445716, l='world', x=-708,62, y=58,00, z=1921,26], jr['TaRhKeR'/1447794, l='world', x=599,56, y=63,00, z=-590,30]]
	Is Modded: Unknown (can't tell)
	Type: Dedicated Server (map_server.txt)