Hi,
I have found a new bug!
I'm not sure how to reproduce this bug, but it suuure is annoying! What happens is your chunks do not load (or flash), and you can't fix it in settings!
After a while, it crashes. Then you start it back up, and it crashes again! Here is the startup log.
^Feb 10, 2015 3:02:04 PM net.minecraft.launchwrapper.LogWrapper log
INFO: Loading tweak class name optifine.OptiFineTweaker
Feb 10, 2015 3:02:04 PM net.minecraft.launchwrapper.LogWrapper log
INFO: Using primary tweak class name optifine.OptiFineTweaker
Feb 10, 2015 3:02:04 PM net.minecraft.launchwrapper.LogWrapper log
INFO: Calling tweak class optifine.OptiFineTweaker
OptiFineTweaker: acceptOptions
OptiFineTweaker: injectIntoClassLoader skipped, OptiFine is loaded as a library
OptiFineTweaker: getLaunchArguments
OptiFineTweaker: getLaunchTarget
Feb 10, 2015 3:02:04 PM net.minecraft.launchwrapper.LogWrapper log
INFO: Launching wrapped minecraft

[15:02:06] [Client thread/INFO]: Setting user: _Roofer
[15:02:06] [Client thread/INFO]: (Session ID is token:bc5e6d1a685f4e33899db6f534ace1ee:65dddb7b592d4b53865f18f9c49099ed)
[OptiFine] (Reflector) Method not pesent: ato.func_149713_g
[15:02:09] [Client thread/INFO]: LWJGL Version: 2.9.1
[OptiFine]
[OptiFine] OptiFine_1.8.1_HD_U_C7
[OptiFine] Tue Feb 10 15:02:09 PST 2015
[OptiFine] OS: Windows 8.1 (amd64) version 6.3
[OptiFine] Java: 1.8.0_25, Oracle Corporation
[OptiFine] VM: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
[OptiFine] LWJGL: 2.9.1
[OptiFine] OpenGL: Intel(R) HD Graphics 4000, version 4.0.0 - Build 10.18.10.3958, Intel
[OptiFine] OpenGL Version: 4.0
[OptiFine] OpenGL Fancy fog: Not available (GL_NV_fog_distance)
[OptiFine] Maximum texture size: 8192x8192
[OptiFine] Checking for new version
[15:02:09] [Client thread/INFO]: Reloading ResourceManager: Default
[OptiFine] *** Reloading textures ***
[OptiFine] Resource packs: Default
[OptiFine] Version found: C7
[15:02:10] [Sound Library Loader/INFO]: Starting up SoundSystem...
[15:02:10] [Thread-7/INFO]: Initializing LWJGL OpenAL
[15:02:10] [Thread-7/INFO]: (The LWJGL binding of OpenAL. For more information, see http://www.lwjgl.org)
AL lib: (EE) MMDevApiOpenPlayback: Device init failed: 0x80004005
AL lib: (EE) MMDevApiOpenPlayback: Device init failed: 0x80004005
[15:02:10] [Thread-7/ERROR]: Error in class 'LibraryLWJGLOpenAL'
[15:02:10] [Thread-7/ERROR]: Unable to initialize OpenAL. Probable cause: OpenAL not supported.
[15:02:10] [Thread-7/WARN]: ERROR MESSAGE:
[15:02:10] [Thread-7/INFO]: Could not locate OpenAL library.
[15:02:10] [Thread-7/WARN]: STACK TRACE:
[15:02:10] [Thread-7/INFO]: org.lwjgl.openal.AL.create(AL.java:151)
[15:02:10] [Thread-7/INFO]: org.lwjgl.openal.AL.create(AL.java:102)
[15:02:10] [Thread-7/INFO]: org.lwjgl.openal.AL.create(AL.java:201)
[15:02:10] [Thread-7/INFO]: paulscode.sound.libraries.LibraryLWJGLOpenAL.init(LibraryLWJGLOpenAL.java:164)
[15:02:10] [Thread-7/INFO]: paulscode.sound.SoundSystem.CommandNewLibrary(SoundSystem.java:1576)
[15:02:10] [Thread-7/INFO]: paulscode.sound.SoundSystem.CommandQueue(SoundSystem.java:2572)
[15:02:10] [Thread-7/INFO]: paulscode.sound.CommandThread.run(CommandThread.java:121)
[15:02:10] [Sound Library Loader/WARN]: ERROR MESSAGE:
[15:02:10] [Sound Library Loader/INFO]: Could not locate OpenAL library.
[15:02:10] [Sound Library Loader/INFO]: Starting up SoundSystem...
[15:02:11] [Thread-9/INFO]: Switching to No Sound
[15:02:11] [Thread-9/INFO]: (Silent Mode)
[15:02:11] [Sound Library Loader/INFO]: Sound engine started
[OptiFine] (Reflector) Class not present: ModLoader
[OptiFine] (Reflector) Class not present: net.minecraft.src.FMLRenderAccessLibrary
[OptiFine] (Reflector) Class not present: LightCache
[OptiFine] (Reflector) Class not present: BlockCoord
[OptiFine] (Reflector) Class not present: net.minecraftforge.common.MinecraftForge
[OptiFine] (Reflector) Class not present: net.minecraftforge.common.ForgeHooks
[OptiFine] (Reflector) Class not present: net.minecraftforge.client.MinecraftForgeClient
[OptiFine] (Reflector) Class not present: net.minecraftforge.client.ForgeHooksClient
[OptiFine] (Reflector) Class not present: net.minecraftforge.fml.common.FMLCommonHandler
[OptiFine] (Reflector) Class not present: net.minecraftforge.fml.client.FMLClientHandler
[OptiFine] (Reflector) Class not present: net.minecraftforge.client.IItemRenderer$ItemRenderType
[OptiFine] (Reflector) Method not pesent: bgb.getSkyRenderer
[OptiFine] (Reflector) Method not pesent: bgb.getCloudRenderer
[OptiFine] (Reflector) Method not pesent: bgb.getWeatherRenderer
[OptiFine] (Reflector) Method not pesent: aqr.countEntities
[OptiFine] (Reflector) Method not pesent: aqr.getPerWorldStorage
[OptiFine] (Reflector) Class not present: net.minecraftforge.client.IRenderHandler
[OptiFine] (Reflector) Class not present: net.minecraftforge.common.DimensionManager
[OptiFine] (Reflector) Class not present: net.minecraftforge.event.world.WorldEvent$Load
[OptiFine] (Reflector) Class not present: net.minecraftforge.client.event.GuiScreenEvent$DrawScreenEvent$Pre
[OptiFine] (Reflector) Class not present: net.minecraftforge.client.event.GuiScreenEvent$DrawScreenEvent$Post
[OptiFine] (Reflector) Class not present: net.minecraftforge.client.event.EntityViewRenderEvent$FogColors
[OptiFine] (Reflector) Class not present: net.minecraftforge.client.event.EntityViewRenderEvent$FogDensity
[OptiFine] (Reflector) Class not present: net.minecraftforge.client.event.EntityViewRenderEvent$RenderFogEvent
[OptiFine] (Reflector) Class not present: net.minecraftforge.fml.common.eventhandler.EventBus
[OptiFine] (Reflector) Class not present: net.minecraftforge.fml.common.eventhandler.Event$Result
[OptiFine] (Reflector) Class not present: net.minecraftforge.event.ForgeEventFactory
[OptiFine] (Reflector) Class not present: net.minecraftforge.event.world.ChunkWatchEvent$UnWatch
[OptiFine] (Reflector) Method not pesent: ato.getBedDirection
[OptiFine] (Reflector) Method not pesent: ato.isBedFoot
[OptiFine] (Reflector) Method not pesent: ato.hasTileEntity
[OptiFine] (Reflector) Method not pesent: ato.canCreatureSpawn
[OptiFine] (Reflector) Method not pesent: ato.addHitEffects
[OptiFine] (Reflector) Method not pesent: ato.addDestroyEffects
[OptiFine] (Reflector) Method not pesent: ato.isAir
[OptiFine] (Reflector) Field not present: wx.captureDrops
[OptiFine] (Reflector) Field not present: wx.capturedDrops
[OptiFine] (Reflector) Method not pesent: wx.shouldRenderInPass
[OptiFine] (Reflector) Method not pesent: wx.canRiderInteract
[OptiFine] (Reflector) Method not pesent: bck.shouldRenderInPass
[OptiFine] (Reflector) Method not pesent: bck.getRenderBoundingBox
[OptiFine] (Reflector) Method not pesent: bck.canRenderBreaking
[OptiFine] (Reflector) Method not pesent: aln.onEntitySwing
[OptiFine] (Reflector) Method not pesent: ws.isCurativeItem
[OptiFine] (Reflector) Method not pesent: amv.getRecordResource
[OptiFine] Multitexture: false
[15:02:13] [Client thread/INFO]: Created: 512x512 textures-atlas
[OptiFine] *** Reloading custom textures ***
[OptiFine] Loading custom colors: textures/colormap/grass.png
[OptiFine] Loading custom colors: textures/colormap/foliage.png
[15:02:27] [Client thread/INFO]: Connecting to mc.tkumain.co.uk, 25565
[15:02:30] [Client thread/INFO]: [CHAT]
[15:02:30] [Client thread/INFO]: [CHAT]
[15:02:30] [Client thread/INFO]: [CHAT] --------------- * ---------------
[15:02:30] [Client thread/INFO]: [CHAT]
[15:02:30] [Client thread/INFO]: [CHAT] Vote now: /vote
[15:02:30] [Client thread/INFO]: [CHAT]
[15:02:30] [Client thread/INFO]: [CHAT] --------------- * ---------------
[15:02:30] [Client thread/INFO]: [CHAT]
[15:02:30] [Client thread/INFO]: [CHAT]
[15:02:30] [Client thread/INFO]: [CHAT] [TKU] Welcome to The Kingdoms United Network.
[15:02:30] [Client thread/INFO]: [CHAT] [TKU] Click the Game Selector to play!^

If you need more information, please leave a reply!

ALSO: It still crashes without optifine!