You say you symbolicated it in Xcode, but I see unresolved addresses in frames 1, 2, 15, and 16 of the stack trace, in code loaded from something called “Chapter3 Framework”, which must be part of your app since it's not an Apple framework. You need to get the .dSYM
file for the version of “Chapter3 Framework” in your app.
Frame 3 of the stack trace is in -[UIApplication _handleApplicationSuspend:eventInfo:]
and frame 2 is in some function in “Chapter3 Framework”. The tester at Apple probably switched away from your app, which puts it in the background. When an app enters the background, it sends the message applicationDidEnterBackground:
to the app delegate. So I guess frame 2 is in your app delegate's applicationDidEnterBackground:
method. Did you test switching away from your app? Did you test switching away from it lots of times, with your app in different states?
The crash report says it crashed on iOS 5.0.1. Did you test switching away from your app on iOS 5.0.1?
The crash report says it crashed on an “iPhone4,1”, which is an iPhone 4S. Did you test switching away from your app on an iPhone 4S?
Did you test switching away from your app on iOS 5.0.1 on an iPhone 4S?
Did you test switching away from your app on a clean install of your app on iOS 5.0.1 on an iPhone 4S?