Just when the latest snapshop starts up, while in the menu and playing the game (survival and creative); the console gives the following:

"Bootstrap (v5)
Current time is Oct 24, 2013 4:34:25 PM
System.getProperty('os.name') == 'Windows 7'
System.getProperty('os.version') == '6.1'
System.getProperty('os.arch') == 'amd64'
System.getProperty('java.version') == '1.7.0_40'
System.getProperty('java.vendor') == 'Oracle Corporation'
System.getProperty('sun.arch.data.model') == '64'

Looking for update
Downloading: https://s3.amazonaws.com/Minecraft.Download/launcher/launcher.pack.lzma
Got reply in: 535ms
No update found.
Reversing LZMA on E:\JPortable\.minecraft\launcher.pack.lzma to E:\JPortable\.minecraft\launcher.pack
Unpacking E:\JPortable\.minecraft\launcher.pack to E:\JPortable\.minecraft\launcher.jar
Cleaning up E:\JPortable\.minecraft\launcher.pack
Starting launcher.
resourceUrl = https://s3.amazonaws.com/Minecraft.Resources/
Refreshing local version list...
Launcher 1.2.7 (through bootstrap 5) started on windows...
Current time is Oct 24, 2013 4:34:27 PM
System.getProperty('os.name') == 'Windows 7'
System.getProperty('os.version') == '6.1'
System.getProperty('os.arch') == 'amd64'
System.getProperty('java.version') == '1.7.0_40'
System.getProperty('java.vendor') == 'Oracle Corporation'
System.getProperty('sun.arch.data.model') == '64'
Refreshing remote version list...
Refresh complete.
Loaded 2 profile(s); selected 'Experimental Builds'
Refreshing auth...
Logging in with access token
resourceUrl = https://s3.amazonaws.com/Minecraft.Resources/?marker=sounds/mob/villager/
Delta time to compare resources: 2263 ms
Download job 'Resources' skipped as there are no files to download
Job 'Resources' finished successfully
Getting syncinfo for selected version
Queueing library & version downloads
Download job 'Version & Libraries' started (8 threads, 24 files)
Finished downloading E:\JPortable\.minecraft\libraries\org\apache\logging\log4j\log4j-api\2.0-beta9\log4j-api-2.0-beta9.jar for job 'Version & Libraries': Used own copy as it matched etag
Finished downloading E:\JPortable\.minecraft\libraries\commons-io\commons-io\2.4\commons-io-2.4.jar for job 'Version & Libraries': Used own copy as it matched etag
Finished downloading E:\JPortable\.minecraft\libraries\com\paulscode\soundsystem\20120107\soundsystem-20120107.jar for job 'Version & Libraries': Used own copy as it matched etag
Finished downloading E:\JPortable\.minecraft\libraries\net\sf\jopt-simple\jopt-simple\4.5\jopt-simple-4.5.jar for job 'Version & Libraries': Used own copy as it matched etag
Finished downloading E:\JPortable\.minecraft\libraries\com\paulscode\codecjorbis\20101023\codecjorbis-20101023.jar for job 'Version & Libraries': Used own copyas it matched etag
Finished downloading E:\JPortable\.minecraft\libraries\java3d\vecmath\1.3.1\vecmath-1.3.1.jar for job 'Version & Libraries': Used own copy as it matched etag
Finished downloading E:\JPortable\.minecraft\libraries\net\java\jinput\jinput-platform\2.0.5\jinput-platform-2.0.5-natives-windows.jar for job 'Version & Libraries': Used own copy as it matched etag
Finished downloading E:\JPortable\.minecraft\libraries\org\lwjgl\lwjgl\lwjgl\2.9.0\lwjgl-2.9.0.jar for job 'Version & Libraries': Used own copy as it matched etag
Finished downloading E:\JPortable\.minecraft\libraries\com\ibm\icu\icu4j-core-mojang\51.2\icu4j-core-mojang-51.2.jar for job 'Version & Libraries': Used own copy as it matched etag
Finished downloading E:\JPortable\.minecraft\libraries\org\lwjgl\lwjgl\lwjgl-platform\2.9.0\lwjgl-platform-2.9.0-natives-windows.jar for job 'Version & Libraries': Used own copy as it matched etag
Finished downloading E:\JPortable\.minecraft\libraries\com\mojang\authlib\1.2\authlib-1.2.jar for job 'Version & Libraries': Used own copy as it matched etag
Finished downloading E:\JPortable\.minecraft\libraries\com\paulscode\libraryjavasound\20101123\libraryjavasound-20101123.jar for job 'Version & Libraries': Used own copy as it matched etag
Finished downloading E:\JPortable\.minecraft\libraries\com\paulscode\codecwav\20101023\codecwav-20101023.jar for job 'Version & Libraries': Used own copy as it matched etag
Finished downloading E:\JPortable\.minecraft\libraries\org\lwjgl\lwjgl\lwjgl_util\2.9.0\lwjgl_util-2.9.0.jar for job 'Version & Libraries': Used own copy as it matched etag
Finished downloading E:\JPortable\.minecraft\libraries\org\apache\logging\log4j\log4j-core\2.0-beta9\log4j-core-2.0-beta9.jar for job 'Version & Libraries': Used own copy as it matched etag
Finished downloading E:\JPortable\.minecraft\libraries\net\java\jutils\jutils\1.0.0\jutils-1.0.0.jar for job 'Version & Libraries': Used own copy as it matched etag
Finished downloading E:\JPortable\.minecraft\libraries\io\netty\netty-all\4.0.10.Final\netty-all-4.0.10.Final.jar for job 'Version & Libraries': Used own copy as it matched etag
Finished downloading E:\JPortable\.minecraft\libraries\org\apache\commons\commons-lang3\3.1\commons-lang3-3.1.jar for job 'Version & Libraries': Used own copy as it matched etag
Finished downloading E:\JPortable\.minecraft\libraries\com\paulscode\librarylwjglopenal\20100824\librarylwjglopenal-20100824.jar for job 'Version & Libraries':Used own copy as it matched etag
Finished downloading E:\JPortable\.minecraft\libraries\net\java\jinput\jinput\2.0.5\jinput-2.0.5.jar for job 'Version & Libraries': Used own copy as it matchedetag
Finished downloading E:\JPortable\.minecraft\libraries\com\google\code\gson\gson\2.2.4\gson-2.2.4.jar for job 'Version & Libraries': Used own copy as it matched etag
Finished downloading E:\JPortable\.minecraft\libraries\com\google\guava\guava\15.0\guava-15.0.jar for job 'Version & Libraries': Used own copy as it matched etag
Finished downloading E:\JPortable\.minecraft\versions\1.7.1\1.7.1.jar for job 'Version & Libraries': Used own copy as it matched etag
Finished downloading E:\JPortable\.minecraft\libraries\net\sf\trove4j\trove4j\3.0.3\trove4j-3.0.3.jar for job 'Version & Libraries': Used own copy as it matched etag
Job 'Version & Libraries' finished successfully
Launching game
Looking for old natives to clean up...
Unpacking natives to E:\JPortable\.minecraft\versions\1.7.1\1.7.1-natives-209598
01536384
Launching in E:\JPortable\.minecraft.experimental
Running E:\JPortable\CommonFiles\Java64\bin\javaw.exe -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx3096M -Xms3096M -Djava.library.path=E:\JPortable\.minecraft\versions\1.7.1\1.7.1-natives-20959801536384 -cp E:\JPortable\.minecraft\libraries\java3d\vecmath\1.3.1\vecmath-1.3.1.jar;E:\JPortable\.minecraft\libraries\net\sf\trove4j\trove4j\3.0.3\trove4j-3.0.3.jar;E:\JPortable\.minecraft\libraries\com\ibm\icu\icu4j-core-mojang\51.2\icu4j-core-mojang-51.2.jar;E:\JPortable\.minecraft\libraries\net\sf\jopt-simple\jopt-simple\4.5\jopt-simple-4.5.jar;E:\JPortable\.minecraft\libraries\com\paulscode\codecjorbis\20101023\codecjorbis-20101023.jar;E:\JPortable\.minecraft\libraries\com\paulscode\codecwav\20101023\codecwav-20101023.jar;E:\JPortable\.minecraft\libraries\com\paulscode\libraryjavasound\20101123\libraryjavasound-20101123.jar;E:\JPortable\.minecraft\libraries\com\paulscode\librarylwjglopenal\20100824\librarylwjglopenal-20100824.jar;E:\JPortable\.minecraft\libraries\com\paulscode\soundsystem\20120107\soundsystem-20120107.jar;E:\JPortable\.minecraft\libraries\io\netty\netty-all\4.0.10.Final\netty-all-4.0.10.Final.jar;E:\JPortable\.minecraft\libraries\com\google\guava\guava\15.0\guava-15.0.jar;E:\JPortable\.minecraft\libraries\org\apache\commons\commons-lang3\3.1\commons-lang3-3.1.jar;E:\JPortable\.minecraft\libraries\commons-io\commons-io\2.4\commons-io-2.4.jar;E:\JPortable\.minecraft\libraries\net\java\jinput\jinput\2.0.5\jinput-2.0.5.jar;E:\JPortable\.minecraft\libraries\net\java\jutils\jutils\1.0.0\jutils-1.0.0.jar;E:\JPortable\.minecraft\libraries\com\google\code\gson\gson\2.2.4\gson-2.2.4.jar;E:\JPortable\.minecraft\libraries\com\mojang\authlib\1.2\authlib-1.2.jar;E:\JPortable\.minecraft\libraries\org\apache\logging\log4j\log4j-api\2.0-beta9\log4j-api-2.0-beta9.jar;E:\JPortable\.minecraft\libraries\org\apache\logging\log4j\log4j-core\2.0-beta9\log4j-core-2.0-beta9.jar;E:\JPortable\.minecraft\libraries\org\lwjgl\lwjgl\lwjgl\2.9.0\lwjgl-2.9.0.jar;E:\JPortable\.minecraft\libraries\org\lwjgl\lwjgl\lwjgl_util\2.9.0\lwjgl_util-2.9.0.jar;E:\JPortable\.minecraft\versions\1.7.1\1.7.1.jar
net.minecraft.client.main.Main --username <redacted> --version 1.7.1 --gameDir E:\JPortable\.minecraft.experimental --assetsDir E:\JPortable\.minecraft\assets --uuid 8c2d975d3ab247aeb173ecb7082c4c4a --accessToken 86af112f067a406795e83c0c5bab3add
Client> [16:34:36] [main/INFO]: Setting user: <redacted>
Client> [16:34:36] [main/INFO]: (Session ID is token:86af112f067a406795e83c0c5bab3add:8c2d975d3ab247aeb173ecb7082c4c4a)
Client> [16:34:36] [Client thread/INFO]: LWJGL Version: 2.9.0
Client> [16:34:37] [Client thread/INFO]: Reloading ResourceManager: Default
Client>
Client> Starting up SoundSystem...
Client> Initializing LWJGL OpenAL
Client> (The LWJGL binding of OpenAL. For more information, see http://www.lwjgl.org)
Client> OpenAL initialized.
Client>
Client> [16:34:38] [Client thread/INFO]: Created: 512x256 textures/blocks-atlas
Client> [16:34:38] [Client thread/INFO]: Created: 256x256 textures/items-atlas
Client> [16:34:44] [Client thread/WARN]: Unable to play empty soundEvent: minecraft:music.menu"

It keeps spamming the console every 5 ~ 10 seconds in both gamemodes and in the menu (not playing).
The game plays without any problem and doesn't crash