Share your experience!
I activated the fly mode and then restarted the phone. It seems to freeze at startup after SONY logo.
Black screen remains for over 5 minutes so I have to restart the phone with red button, then it works again.
Generally boot take long times, I hope Sony will fix all the problem in next firmware release... 
Unfortunately I am unable to reproduce the problem. Do you experience the same problem if you remove the SIM-card in the phone?
The problem is fixed on new firmware G.2.257 🙂