Screen keeps flickering and showing me my background

Please force a crash by pressing F3 + C for 10 seconds while ingame and attach the crash report here.

---- Minecraft Crash Report ----
// This doesn't make any sense!

Time: 8-7-13 12:08
Description: Manually triggered debug crash

java.lang.Throwable
	at atn.k(SourceFile:1232)
	at atn.S(SourceFile:662)
	at atn.d(SourceFile:618)
	at net.minecraft.client.main.Main.main(SourceFile:101)


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

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [bcx['xThijs123'/216, l='MpServer', x=-227,69, y=64,62, z=206,76]]
	Chunk stats: MultiplayerChunkCache: 441
	Level seed: 0
	Level generator: ID 00 - default, ver 1. Features enabled: false
	Level generator options: 
	Level spawn location: World: (-158,64,308), Chunk: (at 2,4,4 in -10,19; contains blocks -160,0,304 to -145,255,319), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
	Level time: 17342 game time, 17342 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: 82 total; [tc['Creeper'/137, l='MpServer', x=-198,50, y=63,00, z=224,50], tc['Creeper'/136, l='MpServer', x=-197,53, y=28,00, z=212,94], rw['Sheep'/139, l='MpServer', x=-213,47, y=70,00, z=246,16], rw['Sheep'/138, l='MpServer', x=-194,19, y=64,00, z=238,47], rw['Sheep'/140, l='MpServer', x=-207,22, y=74,00, z=242,81], tt['Zombie'/131, l='MpServer', x=-197,50, y=18,00, z=198,50], rl['Bat'/130, l='MpServer', x=-205,25, y=19,10, z=137,25], to['Skeleton'/133, l='MpServer', x=-193,50, y=61,97, z=197,78], tt['Zombie'/132, l='MpServer', x=-200,06, y=17,00, z=194,41], to['Skeleton'/135, l='MpServer', x=-192,09, y=49,00, z=207,50], tc['Creeper'/134, l='MpServer', x=-192,63, y=63,00, z=200,94], tc['Creeper'/152, l='MpServer', x=-190,50, y=63,00, z=225,50], rw['Sheep'/153, l='MpServer', x=-191,34, y=64,00, z=240,44], rz['Squid'/145, l='MpServer', x=-188,25, y=57,38, z=165,44], tc['Creeper'/146, l='MpServer', x=-184,94, y=35,00, z=205,22], tc['Creeper'/147, l='MpServer', x=-185,00, y=35,00, z=203,75], tc['Creeper'/148, l='MpServer', x=-177,66, y=36,00, z=210,97], to['Skeleton'/149, l='MpServer', x=-189,06, y=48,00, z=206,56], tc['Creeper'/150, l='MpServer', x=-187,50, y=35,00, z=209,50], to['Skeleton'/151, l='MpServer', x=-182,50, y=57,00, z=228,88], rv['Pig'/170, l='MpServer', x=-169,97, y=64,00, z=267,50], tc['Creeper'/166, l='MpServer', x=-165,56, y=43,88, z=234,88], sp['item.tile.sapling.oak'/165, l='MpServer', x=-171,09, y=64,13, z=220,81], tt['Zombie'/164, l='MpServer', x=-169,59, y=63,00, z=215,03], tt['Zombie'/51, l='MpServer', x=-305,16, y=11,00, z=280,50], sr['entity.MinecartChest.name'/55, l='MpServer', x=-299,50, y=47,50, z=154,50], rl['Bat'/59, l='MpServer', x=-301,25, y=19,10, z=249,44], tt['Zombie'/58, l='MpServer', x=-294,16, y=79,00, z=220,72], rv['Pig'/57, l='MpServer', x=-303,50, y=63,00, z=168,97], sr['entity.MinecartChest.name'/56, l='MpServer', x=-299,50, y=47,50, z=160,50], sp['item.tile.sapling.oak'/63, l='MpServer', x=-289,72, y=73,13, z=270,03], rw['Sheep'/62, l='MpServer', x=-302,66, y=75,00, z=268,50], sp['item.tile.sapling.oak'/61, l='MpServer', x=-288,13, y=90,13, z=246,69], rw['Sheep'/60, l='MpServer', x=-303,16, y=78,00, z=246,97], rn['Chicken'/71, l='MpServer', x=-274,31, y=91,00, z=127,47], rl['Bat'/64, l='MpServer', x=-295,45, y=28,93, z=285,48], tc['Creeper'/76, l='MpServer', x=-278,50, y=78,00, z=243,50], rw['Sheep'/77, l='MpServer', x=-284,41, y=70,00, z=267,03], tt['Zombie'/468, l='MpServer', x=-274,50, y=72,00, z=252,50], rw['Sheep'/78, l='MpServer', x=-277,19, y=64,00, z=269,59], rw['Sheep'/79, l='MpServer', x=-284,34, y=68,00, z=268,75], rn['Chicken'/72, l='MpServer', x=-272,50, y=90,00, z=128,50], tt['Zombie'/467, l='MpServer', x=-275,50, y=72,00, z=252,50], rv['Pig'/73, l='MpServer', x=-287,50, y=64,00, z=162,50], tt['Zombie'/74, l='MpServer', x=-275,50, y=79,00, z=209,50], sp['item.tile.cloth.white'/465, l='MpServer', x=-171,47, y=64,13, z=236,78], rl['Bat'/75, l='MpServer', x=-287,25, y=19,10, z=252,50], rw['Sheep'/85, l='MpServer', x=-263,34, y=68,00, z=184,50], rw['Sheep'/84, l='MpServer', x=-257,53, y=67,00, z=182,38], rw['Sheep'/87, l='MpServer', x=-258,13, y=68,00, z=218,53], rw['Sheep'/86, l='MpServer', x=-261,13, y=64,00, z=203,19], rw['Sheep'/83, l='MpServer', x=-257,81, y=70,00, z=188,84], rn['Chicken'/82, l='MpServer', x=-278,53, y=83,00, z=140,47], rl['Bat'/93, l='MpServer', x=-254,13, y=11,49, z=143,91], tt['Zombie'/92, l='MpServer', x=-259,50, y=63,00, z=141,28], rw['Sheep'/95, l='MpServer', x=-250,50, y=63,00, z=175,06], rl['Bat'/94, l='MpServer', x=-238,11, y=14,86, z=189,45], td['Enderman'/89, l='MpServer', x=-264,53, y=26,00, z=251,00], tc['Creeper'/88, l='MpServer', x=-276,69, y=86,00, z=221,47], tq['Spider'/91, l='MpServer', x=-255,00, y=64,00, z=128,06], bcx['xThijs123'/216, l='MpServer', x=-227,69, y=64,62, z=206,76], rw['Sheep'/96, l='MpServer', x=-253,03, y=66,00, z=179,22], rw['Sheep'/97, l='MpServer', x=-242,09, y=65,00, z=223,53], to['Skeleton'/110, l='MpServer', x=-232,34, y=22,00, z=213,34], tt['Zombie'/111, l='MpServer', x=-233,03, y=24,00, z=223,38], to['Skeleton'/108, l='MpServer', x=-230,50, y=22,00, z=208,50], to['Skeleton'/109, l='MpServer', x=-232,41, y=22,00, z=210,88], to['Skeleton'/106, l='MpServer', x=-233,50, y=24,00, z=204,50], rz['Squid'/105, l='MpServer', x=-224,03, y=56,00, z=168,50], to['Skeleton'/119, l='MpServer', x=-208,50, y=17,00, z=145,50], tc['Creeper'/118, l='MpServer', x=-223,50, y=68,00, z=129,50], to['Skeleton'/117, l='MpServer', x=-211,66, y=17,00, z=142,88], to['Skeleton'/114, l='MpServer', x=-234,50, y=13,00, z=266,06], tc['Creeper'/113, l='MpServer', x=-232,50, y=38,00, z=235,50], tc['Creeper'/112, l='MpServer', x=-233,50, y=38,00, z=236,50], rw['Sheep'/126, l='MpServer', x=-210,34, y=68,00, z=241,50], to['Skeleton'/125, l='MpServer', x=-213,38, y=63,00, z=224,91], tt['Zombie'/124, l='MpServer', x=-226,03, y=25,00, z=228,47], tc['Creeper'/123, l='MpServer', x=-213,31, y=63,00, z=211,91], to['Skeleton'/122, l='MpServer', x=-201,78, y=63,00, z=199,78], rl['Bat'/121, l='MpServer', x=-220,51, y=18,11, z=200,69], to['Skeleton'/120, l='MpServer', x=-210,50, y=17,00, z=144,50]]
	Retry entities: 0 total; []
Stacktrace:
	at bcu.a(SourceFile:284)
	at atn.b(SourceFile:1743)
	at atn.d(SourceFile:627)
	at net.minecraft.client.main.Main.main(SourceFile:101)

-- System Details --
Details:
	Minecraft Version: 1.6.1
	Operating System: Windows 7 (amd64) version 6.1
	Java Version: 1.6.0_27, Sun Microsystems Inc.
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Sun Microsystems Inc.
	Memory: 113637480 bytes (108 MB) / 336265216 bytes (320 MB) up to 3817799680 bytes (3640 MB)
	JVM Flags: 1 total; -Xmx4G
	AABB Pool Size: 7389 (413784 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
	Launched Version: 1.6.1
	LWJGL: 2.9.0
	OpenGL: GeForce GT 630/PCIe/SSE2 GL version 4.3.0, NVIDIA Corporation
	Is Modded: Probably not. Jar signature remains and client brand is untouched.
	Type: Client (map_client.txt)
	Resource Pack: Default
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 2244 (125664 bytes; 0 MB) allocated, 17 (952 bytes; 0 MB) used

Your Java is out of date. Please update your Java to the latest version: http://www.java.com/en/download/ . Keep in mind that when using a 32-bit browser on a 64-bit OS the automatic version detection will only show the 32-bit version of Java, the 64-bit version needs to be downloaded manually: http://www.java.com/en/download/manual.jsp .

Please report if the issue persists with the latest Java version

This helped a bit.
the problem is still there but less more often.

Is this still a concern in the current Minecraft version? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.

Please force a new crash by pressing F3 + C for 10 seconds while ingame and attach the crash report ([minecraft|http://hopper.minecraft.net/help/finding-minecraft-data-folder]/crash-reports/crash-<DATE>-client.txt) here.

here is the crash report

Your Java is still out of date. According to the crash report you updated the 32-bit version of Java but not the 64-bit version which Minecraft is using...

Java Version: 1.6.0_27, Sun Microsystems Inc.
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Sun Microsystems Inc.

Please update the 64-bit version of your Java using the instructions provided in the previous comment.

it helped but my main problem is now that i sometimes can't press the respawn button when i died.
any suggestions on how to fix that?

Your Minecraft window is resizing permanently, thus duplicate of MC-26846