Im having a weird problem with my lumia 720, running wp 8.1. Firstly, the phone hangs sometimes if u enter your password on the lock screen. The only solution to make it work is a soft reset. BUT, the problem stays there after several resets! Phone switches on, you enter your password and BOOM! it hangs again :/ I even got a blue screen with a sad smiley after a Nokia Logo. Thought I bricked it. But a soft reset helped overcome it. Somehow it didnt hang this time and I removed the lock screen Anybuddy else with this kinda problem??