Crashed while playing

---- Minecraft Crash Report ----
// Don't do that.

Time: 5/24/13 4:38 PM
Description: Updating screen events

java.lang.ClassCastException: ul cannot be cast to aza
	at ayy.a(SourceFile:175)
	at ayl.b(SourceFile:516)
	at ayy.b(SourceFile:409)
	at axr.d(SourceFile:131)
	at ayy.d(SourceFile:486)
	at axr.m(SourceFile:111)
	at net.minecraft.client.Minecraft.l(SourceFile:1078)
	at net.minecraft.client.Minecraft.K(SourceFile:574)
	at net.minecraft.client.Minecraft.run(SourceFile:526)
	at java.lang.Thread.run(Unknown Source)


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

-- Head --
Stacktrace:
	at ayy.a(SourceFile:175)
	at ayl.b(SourceFile:516)
	at ayy.b(SourceFile:409)
	at axr.d(SourceFile:131)
	at ayy.d(SourceFile:486)
	at axr.m(SourceFile:111)

-- Affected screen --
Details:
	Screen name: ayy

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [bdv['aidansawyer'/133, l='MpServer', x=-344.17, y=5.62, z=-345.63]]
	Chunk stats: MultiplayerChunkCache: 441
	Level seed: 0
	Level generator: ID 01 - flat, ver 0. Features enabled: false
	Level generator options: 
	Level spawn location: World: (-317,4,-322), Chunk: (at 3,0,14 in -20,-21; contains blocks -320,0,-336 to -305,255,-321), Region: (-1,-1; contains chunks -32,-32 to -1,-1, blocks -512,0,-512 to -1,255,-1)
	Level time: 75334 game time, 75334 day time
	Level dimension: 0
	Level storage version: 0x00000 - Unknown?
	Level weather: Rain time: 0 (now: false), thunder time: 0 (now: false)
	Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: false
	Forced entities: 28 total; [sm['Villager'/454465, l='MpServer', x=-342.31, y=4.00, z=-344.31], sm['Villager'/455338, l='MpServer', x=-353.69, y=4.00, z=-360.69], sm['Villager'/455465, l='MpServer', x=-343.13, y=4.00, z=-346.22], bdv['aidansawyer'/133, l='MpServer', x=-344.17, y=5.62, z=-345.63], qo['Sheep'/21, l='MpServer', x=-413.78, y=4.00, z=-406.63], qo['Sheep'/22, l='MpServer', x=-411.94, y=4.00, z=-399.09], qo['Sheep'/27, l='MpServer', x=-395.50, y=4.00, z=-408.50], qo['Sheep'/26, l='MpServer', x=-397.50, y=4.00, z=-406.50], sg['Slime'/497042, l='MpServer', x=-324.09, y=4.47, z=-339.48], sg['Slime'/456052, l='MpServer', x=-424.25, y=4.00, z=-300.86], rh['item.item.rottenFlesh'/456185, l='MpServer', x=-335.28, y=4.13, z=-338.25], rh['item.item.arrow'/456539, l='MpServer', x=-311.59, y=4.13, z=-362.19], rh['item.item.bone'/456540, l='MpServer', x=-310.72, y=4.13, z=-362.97], sm['Villager'/456032, l='MpServer', x=-344.69, y=4.00, z=-344.31], sg['Slime'/502453, l='MpServer', x=-395.06, y=4.00, z=-411.94], rh['item.item.arrow'/457347, l='MpServer', x=-283.19, y=4.13, z=-383.59], sg['Slime'/495403, l='MpServer', x=-389.00, y=4.00, z=-329.44], sg['Slime'/501748, l='MpServer', x=-290.81, y=4.00, z=-287.81], sm['Villager'/83753, l='MpServer', x=-336.50, y=4.00, z=-334.50], sm['Villager'/454061, l='MpServer', x=-343.06, y=4.00, z=-345.47], sg['Slime'/508801, l='MpServer', x=-309.87, y=4.00, z=-338.44], sg['Slime'/521776, l='MpServer', x=-358.90, y=4.00, z=-319.22], sm['Villager'/456924, l='MpServer', x=-361.25, y=4.00, z=-333.25], sm['Villager'/454878, l='MpServer', x=-342.31, y=4.00, z=-346.69], sg['Slime'/539974, l='MpServer', x=-322.40, y=4.53, z=-406.29], rh['item.item.rottenFlesh'/457549, l='MpServer', x=-313.00, y=4.13, z=-402.13], ru['Creeper'/379669, l='MpServer', x=-341.94, y=4.00, z=-354.44], rh['item.item.rottenFlesh'/458375, l='MpServer', x=-390.91, y=4.13, z=-345.97]]
	Retry entities: 0 total; []
Stacktrace:
	at bds.a(SourceFile:282)
	at net.minecraft.client.Minecraft.b(SourceFile:1881)
	at net.minecraft.client.Minecraft.run(SourceFile:535)
	at java.lang.Thread.run(Unknown Source)

-- System Details --
Details:
	Minecraft Version: 1.5.2
	Operating System: Windows Vista (x86) version 6.0
	Java Version: 1.7.0_21, Oracle Corporation
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
	Memory: 215720976 bytes (205 MB) / 519110656 bytes (495 MB) up to 1037959168 bytes (989 MB)
	JVM Flags: 2 total; -Xms512m -Xmx1024m
	AABB Pool Size: 1724 (96544 bytes; 0 MB) allocated, 5 (280 bytes; 0 MB) used
	Suspicious classes: No suspicious classes found.
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	LWJGL: 2.4.2
	OpenGL: Intel 965/963 Graphics Media Accelerator GL version 1.5.0 - Build 7.14.10.1437, Intel
	Is Modded: Probably not. Jar signature remains and client brand is untouched.
	Type: Client (map_client.txt)
	Texture Pack: Default
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 224 (12544 bytes; 0 MB) allocated, 28 (1568 bytes; 0 MB) used