As it turns out, the logging via the Organizer does not seems to be working. According to the technical note, console logging is not available in iOS 6.x. However I could read the log using iTunes.
You must connect your device and synchronize it. After this the crash log should be found here (on Mac OS X):
~/Library/Logs/CrashReporter/MobileDevice/<DEVICE_NAME>/PersistentConnection/
I hope this helps someone.