Application crashes after Game Center integrated (iOS 4.2.1)

I m making an IPhone/IPad game. Integrated Ad-Banner,Store Kit and Game Center. The application works fine when running on IPad2(iOS 5) and IPhone4 (iOS 5)but when the application runs on IPad1 (iOS 4.2.1) it crashes after it goes through some scenes. I disabled game center plugin and run the new built on IPad1 (iOS 4.2.1) and the application works fine.I dont understand where i m going wrong.

i have GameCenterManager on the SlashScreen and authenticated the user on the same screen have an option to Load LeaderBoard on the MainMenuScene,GameScene which posts the score and bunch of other Scene which doesn't use GameCenter... Application crashes some times when it goes to the GameScene else when it comes back to the MainMenuScene from the GameScene...