[MC-16582] Random Crash due to "1.6 has been released" banner.

Every once in a while when I log onto minecraft and
go into my redstone world, I crash and get this error
(as the cause of the crash)

2013-05-26 14:52:34 [SERVER] [INFO] Starting integrated minecraft server version 1.5.2
2013-05-26 14:52:34 [SERVER] [INFO] Generating keypair
2013-05-26 14:52:34 [SERVER] [INFO] Converting map!
2013-05-26 14:52:34 [SERVER] [INFO] Scanning folders...
2013-05-26 14:52:34 [SERVER] [INFO] Total conversion count is 0
2013-05-26 14:52:34 [SERVER] [WARNING] Unable to find spawn biome
java.io.FileNotFoundException: http://assets.minecraft.net/1_6_has_been_released.flag
	at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
	at kn.a(SourceFile:234)
	at bkg.run(SourceFile:113)
	at java.lang.Thread.run(Unknown Source)
2013-05-26 14:52:37 [SERVER] [INFO] Preparing start region for level 0
2013-05-26 14:52:38 [SERVER] [INFO] Preparing spawn area: 32%
2013-05-26 14:52:39 [SERVER] [INFO] Preparing spawn area: 65%
2013-05-26 14:52:40 [SERVER] [INFO] Preparing spawn area: 93%
2013-05-26 14:52:41 [SERVER] [INFO] Yoshidude267410[/127.0.0.1:0] logged in with entity id 1250 at (1372.5, 56.0, -351.5)
java.io.FileNotFoundException: http://assets.minecraft.net/1_6_has_been_released.flag
	at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
	at kn.a(SourceFile:234)
	at bkg.run(SourceFile:113)
	at java.lang.Thread.run(Unknown Source)
Minecraft exited with code -1073740771.
Minecraft has crashed!

I think it is because of that 1.6 banner that they
are adding, but for some reason, its not there.