-Sometimes auto-screen rotate does not work and I will have to restart my phone.
-When I take pictures, the result of the photo is turned a different way and I would have to manually rotate the photo back.
-Sometimes when I take a picture in superior auto mode, it gives me a 1 shot burst. I'm not holding it either. Restarting phone solved this problem.
Two issues that have been around since I first got my phone:
-I have more wi-fi issues with my Z1 than my Z. It often drops signal.
-Camera button sometimes does not work while phone display is off.... however I believe the kitkat update fixed it as I no longer have issues.