When I'm trying to handle physical back button press on Android device via the Keys attached property no expected action happens and app finishes with error "Can't find surface 1". I've tried to follow that recipes:
http://www.qtcentre.org/threads/57795-Android-back-button-handling-is-inconsistent
https://qt.gitorious.org/qt-labs/weather-app/commit/28bc8dcf3a1523658c3d16be45809b7aed188b3c
http://stackoverflow.com/questions/18979198/qt-5-1-android-program-does-not-send-keypresses
http://qt-project.org/forums/viewthread/29366

But nothing helped me.