Application crash on Lock when Japanese keyboard used

The problem appeared on iOS 6. To reproduce it you need to enter text with japanese (kana) keyboard and press on 'Lock' button when suggestions appear. After unlocking user is on application dashboard instead of the application. If press on application icon it's loaded again - app crashed when lock was pressed. It's true even for apple apps like Notes Crash logs: Application Specific Information:

[kazuph1986]

これしかないのか・・・

[rryu]

iOS6の日本語キーボードでクラッシュするのを回避する実装方法。バックグラウンドに回せるアプリにしてそこでキーボードを閉じる。うまく行くかどうかは謎。

[efcl]

iOS6日本語キーボード利用中にスリープでクラッシュ

[tasanobu]

iOS ios6 keyboard キーボード crash クラッシュ

[invent]

iphone - Application crash on Lock when Japanese keyboard used - Stack Overflow