Biblioteca13

Just happened again to me today.

Launcher 1.0.10 (through bootstrap 5) started on windows...
Current time is Jul 14, 2013 5:02:37 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_25'
System.getProperty('java.vendor') == 'Oracle Corporation'
System.getProperty('sun.arch.data.model') == '64'
Loaded 2 profile(s); selected '(Default)'

That happened to me Survival 1.6.1 when creating new fresh world. Win 7, Java 7
[Confirmed]