Transparency problem

The textures would show solid black wherever there's transparency.For example,the head of mobs with biped models would turn black completely (the second head overlay).Also,when I tried to investigate the textures(in minecraft.jar) they seemed to have normal transparency.Even text has no transparency making it impossible to read signs.

Crash report:

Minecraft has crashed!      
      ----------------------      

Minecraft has stopped running because it encountered a problem; Manually triggered debug crash

A full error report has been saved to C:\Users\***\AppData\Roaming\.minecraft\crash-reports\crash-2012-12-08_15.44.21-client.txt - Please include a copy of that file (Not this screen!) if you report this crash to anyone; without it, they will not be able to help fix the crash :(



--- BEGIN ERROR REPORT f572fa38 --------
Full report at:
C:\Users\***\AppData\Roaming\.minecraft\crash-reports\crash-2012-12-08_15.44.21-client.txt
Please show that file to Mojang, NOT just this screen!

Generated 12/8/12 3:44 PM

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [ayk['jiana'/910371, l='MpServer', x=-650.24, y=8.49, z=-850.70]]
	Chunk stats: MultiplayerChunkCache: 441
	Level seed: 0
	Level generator: ID 01 - flat, ver 0. Features enabled: false
	Level generator options: 
	Level spawn location: World: (-818,4,-906), Chunk: (at 14,0,6 in -52,-57; contains blocks -832,0,-912 to -817,255,-897), Region: (-2,-2; contains chunks -64,-64 to -33,-33, blocks -1024,0,-1024 to -513,255,-513)
	Level time: 15997 game time, 15997 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: 79 total; [qu['Villager'/910362, l='MpServer', x=-667.88, y=5.00, z=-832.87], ow['Bat'/910361, l='MpServer', x=-667.81, y=6.10, z=-836.38], qr['Zombie'/910360, l='MpServer', x=-671.78, y=4.00, z=-879.72], ow['Bat'/910367, l='MpServer', x=-644.97, y=4.77, z=-779.31], qu['Villager'/910319, l='MpServer', x=-699.70, y=5.00, z=-830.88], ow['Bat'/910366, l='MpServer', x=-650.47, y=7.10, z=-821.75], qu['Villager'/910318, l='MpServer', x=-697.65, y=5.00, z=-830.31], qc['Creeper'/910317, l='MpServer', x=-698.69, y=4.00, z=-916.63], qp['Spider'/910365, l='MpServer', x=-648.31, y=4.00, z=-902.91], qc['Creeper'/910316, l='MpServer', x=-703.50, y=4.00, z=-913.50], qp['Spider'/910364, l='MpServer', x=-643.72, y=4.00, z=-908.06], qu['Villager'/910307, l='MpServer', x=-714.47, y=5.00, z=-811.56], qu['Villager'/910306, l='MpServer', x=-714.50, y=5.00, z=-810.71], qu['Villager'/910305, l='MpServer', x=-714.61, y=5.00, z=-830.51], qn['Skeleton'/910352, l='MpServer', x=-687.34, y=4.00, z=-771.34], qu['Villager'/910304, l='MpServer', x=-712.00, y=5.00, z=-830.97], pd['Pig'/910359, l='MpServer', x=-660.19, y=4.00, z=-930.50], qn['Skeleton'/910310, l='MpServer', x=-716.59, y=4.00, z=-783.38], qp['Spider'/910309, l='MpServer', x=-712.50, y=4.00, z=-785.25], ow['Bat'/910308, l='MpServer', x=-714.25, y=7.10, z=-810.25], qu['Villager'/910346, l='MpServer', x=-686.31, y=5.00, z=-820.31], qu['Villager'/910330, l='MpServer', x=-695.30, y=5.00, z=-821.30], qu['Villager'/910347, l='MpServer', x=-692.23, y=6.50, z=-822.50], qu['Villager'/910331, l='MpServer', x=-700.50, y=5.00, z=-825.50], qu['Villager'/910328, l='MpServer', x=-700.94, y=5.50, z=-822.72], ow['Bat'/910344, l='MpServer', x=-687.38, y=6.00, z=-844.81], qu['Villager'/910345, l='MpServer', x=-683.47, y=5.00, z=-826.22], qu['Villager'/910329, l='MpServer', x=-701.69, y=5.00, z=-823.81], qu['Villager'/910350, l='MpServer', x=-679.53, y=5.00, z=-805.06], qu['Villager'/910334, l='MpServer', x=-696.16, y=5.00, z=-822.41], qu['Villager'/910335, l='MpServer', x=-695.31, y=5.00, z=-823.32], qu['Villager'/910348, l='MpServer', x=-679.31, y=5.00, z=-814.50], qu['Villager'/910332, l='MpServer', x=-698.95, y=5.00, z=-831.06], qu['Villager'/910349, l='MpServer', x=-678.91, y=5.00, z=-815.38], qu['Villager'/910333, l='MpServer', x=-697.00, y=5.00, z=-822.05], qu['Villager'/910338, l='MpServer', x=-700.84, y=5.00, z=-824.36], ow['Bat'/910322, l='MpServer', x=-688.25, y=6.10, z=-844.81], qn['Skeleton'/910339, l='MpServer', x=-695.50, y=5.00, z=-819.03], ow['Bat'/910323, l='MpServer', x=-693.59, y=6.10, z=-844.81], qu['Villager'/910336, l='MpServer', x=-687.22, y=5.00, z=-821.22], qu['Villager'/910320, l='MpServer', x=-695.33, y=5.00, z=-832.31], qu['Villager'/910337, l='MpServer', x=-699.72, y=5.00, z=-824.03], ow['Bat'/910321, l='MpServer', x=-692.53, y=6.10, z=-844.81], ow['Bat'/910342, l='MpServer', x=-687.25, y=6.10, z=-844.81], qu['Villager'/910326, l='MpServer', x=-701.69, y=6.00, z=-821.84], ow['Bat'/910343, l='MpServer', x=-686.06, y=7.10, z=-845.25], qu['Villager'/910327, l='MpServer', x=-698.84, y=5.00, z=-830.30], qr['Zombie'/910340, l='MpServer', x=-678.50, y=4.00, z=-886.50], qu['Villager'/910324, l='MpServer', x=-701.70, y=5.00, z=-824.68], ow['Bat'/910341, l='MpServer', x=-686.25, y=7.10, z=-845.50], qu['Villager'/910325, l='MpServer', x=-700.00, y=5.00, z=-823.13], qr['Zombie'/910392, l='MpServer', x=-573.72, y=4.00, z=-860.22], qd['Enderman'/910385, l='MpServer', x=-577.88, y=4.00, z=-872.53], qd['Enderman'/910384, l='MpServer', x=-583.50, y=4.00, z=-869.84], qc['Creeper'/910387, l='MpServer', x=-577.88, y=4.00, z=-869.04], qc['Creeper'/910386, l='MpServer', x=-585.50, y=4.00, z=-864.50], qn['Skeleton'/910389, l='MpServer', x=-590.69, y=4.00, z=-857.66], qn['Skeleton'/910388, l='MpServer', x=-590.06, y=4.00, z=-860.53], qn['Skeleton'/910376, l='MpServer', x=-596.59, y=4.00, z=-834.78], qd['Enderman'/910297, l='MpServer', x=-710.50, y=4.00, z=-920.13], qn['Skeleton'/910377, l='MpServer', x=-595.50, y=4.00, z=-838.50], ow['Bat'/910298, l='MpServer', x=-712.50, y=8.10, z=-838.75], qp['Spider'/910378, l='MpServer', x=-594.63, y=4.00, z=-835.75], qu['Villager'/910299, l='MpServer', x=-713.84, y=5.00, z=-823.22], qp['Spider'/910379, l='MpServer', x=-593.50, y=4.00, z=-830.50], ow['Bat'/910300, l='MpServer', x=-713.75, y=7.10, z=-817.59], ow['Bat'/910301, l='MpServer', x=-712.75, y=8.10, z=-818.47], ayk['jiana'/910371, l='MpServer', x=-650.24, y=8.49, z=-850.70], ow['Bat'/910302, l='MpServer', x=-714.19, y=7.00, z=-816.25], qc['Creeper'/910382, l='MpServer', x=-583.84, y=4.00, z=-856.88], ow['Bat'/910303, l='MpServer', x=-714.19, y=6.10, z=-818.53], qr['Zombie'/910383, l='MpServer', x=-589.00, y=4.00, z=-864.59], qp['Spider'/910368, l='MpServer', x=-639.78, y=4.00, z=-904.06], qn['Skeleton'/910369, l='MpServer', x=-625.50, y=4.00, z=-838.50], ow['Bat'/910370, l='MpServer', x=-631.66, y=10.77, z=-805.94], qn['Skeleton'/910291, l='MpServer', x=-725.50, y=4.00, z=-868.50], qp['Spider'/910372, l='MpServer', x=-611.50, y=4.00, z=-930.34], qr['Zombie'/910292, l='MpServer', x=-721.50, y=4.00, z=-861.50], qr['Zombie'/910375, l='MpServer', x=-626.38, y=4.00, z=-840.28]]
	Retry entities: 0 total; []
Stacktrace:
	at ayh.a(SourceFile:290)
	at net.minecraft.client.Minecraft.b(SourceFile:1870)
	at net.minecraft.client.Minecraft.run(SourceFile:543)
	at java.lang.Thread.run(Unknown Source)

-- System Details --
Details:
	Minecraft Version: 1.4.5
	Operating System: Windows 7 (x86) version 6.1
	Java Version: 1.7.0_05, Oracle Corporation
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
	Memory: 350686424 bytes (334 MB) / 1037959168 bytes (989 MB) up to 1037959168 bytes (989 MB)
	JVM Flags: 2 total; -Xms512m -Xmx1024m
	AABB Pool Size: 7955 (445480 bytes; 0 MB) allocated, 2 (112 bytes; 0 MB) used
	Suspicious classes: No suspicious classes found.
	IntCache: cache: 0, tcache: 0, allocated: 1, tallocated: 63
	LWJGL: 2.4.2
	OpenGL: Intel(R) Graphics Media Accelerator HD GL version 2.1.0 - Build 8.15.10.1968, 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: 862 (48272 bytes; 0 MB) allocated, 13 (728 bytes; 0 MB) used

java.lang.Throwable
	at net.minecraft.client.Minecraft.l(SourceFile:1171)
	at net.minecraft.client.Minecraft.J(SourceFile:582)
	at net.minecraft.client.Minecraft.run(SourceFile:534)
	at java.lang.Thread.run(Unknown Source)
--- END ERROR REPORT 3fe3aea7 ----------