This is my experience sharing.
I encounter a crash that only happened on device, but not on simulator.
It’s painful to find the bug, but I did find finally.
The reason is simple, I just change my CCSprite action from a single action to CCSequence with multiple actions.
And the stupid thing is that I FORGOT to add an “NULL” at the end of sequencial actions.
Compile is fine, and the simulator runs smoothly, but It crashed when I deployed to my iPhone.
If you find a crash on action execution and that only happend on Device not on simulator.
Go to check all of your CCSequence actions, maybe you will find something that save your time( and time is money).
Hope this will help someone like me.
This article is also post on my Apps blog : http://blog.molioapp.com/2012/04/simple-note-for-on-device-crashcocos2d.html