Since iOS 7 I no longer get the prompt from game center to ask me to log in sandbox mode when I open my application. I searched for a while and never saw any known issues about this and there are no patch notes that says anything about sandbox mode changing. Has anyone encountered this problem?
![Unable to sign in Sandbox gamecenter on iOS 7](https://cdn-ak-scissors.b.st-hatena.com/image/square/98d6f053a97a87156775f60757c60865d0f2c47d/height=288;version=1;width=512/https%3A%2F%2Fcdn.sstatic.net%2FSites%2Fstackoverflow%2FImg%2Fapple-touch-icon%402.png%3Fv%3D73d79a89bded)