I'm having the same issue, and it looks like a bug in the firmware. I had already reported it, let's hope someone is taking care of it.
Here's a sample stack trace from logcat, that nicely shows how a filed mUiMode is not properly initialized when a new DisplayLayout-Object is created:
09-13 21:27:20.823 2872 2872 E AndroidRuntime: FATAL EXCEPTION: main
09-13 21:27:20.823 2872 2872 E AndroidRuntime: Process: com.android.systemui, PID: 2872
09-13 21:27:20.823 2872 2872 E AndroidRuntime: java.lang.NullPointerException: Attempt to read from field 'int com.and