iPad crashes that aren't happening on iPhone or iPod Touch

Question

Has anyone had difficulty getting what has otherwise been a solid iPhone app working on the iPad? I was under the impression that iPhone apps would run without problems on the iPad. We are are experiencing crashes (not intermittent - same place, at same time) that we've never gotten on the iPhone or iPod Touch. I have become suspicious that the crashes are memory-management related, but even if so, why only on the iPad?

    2010-05-17 10:19:06.474 ASSIST[82:207] *** Terminating app due to uncaught 
exception 'NSUnknownKeyException', reason: '[<UISectionRowData 
0x6041480> valueForUndefinedKey:]: this class is not key value coding-compliant 
for the key deliveryDate.'
    2010-05-17 10:19:06.481 ASSIST[82:207] Stack: (
    852041337,
    861292157,
    852040861,
    850755255,
    850750995,
    850758945,
    81279,
    123007,
    126693,
    149141,
    851599725,
    827486573,
    827486477,
    827486431,
    827485745,
    827487359,
    827454123,
    851903137,
    851590065,
    851588321,
    819339483,
    819339655,
    827151561,
    827144691,
    9461,
    9324
    )
    terminate called after throwing an instance of 'NSException'
Program received signal:  “SIGABRT”.

Answer 1

[ valueForUndefinedKey:]: this class is not key value coding-compliant for the key deliveryDate implies a possible constant that does not apply to iPad. Try using NSLog() to track down the buggy code.

Answer 2

It looks like memory issue. Probably you should use NSZombie to check what's wrong, and use the "Build and Analyze" option to check statically for any memory management problems.

About why iPad crashes but iPhone does not — remember that iPad runs on iPhoneOS 3.2, while the iPhone is still running 3.1. The internals could be changed a lot. Of course the "iPhone simulation mode" on the iPad is running 3.2 code.

Therefore, a possibility is you have a memory management bug in the original software. The object got -retained internally in the old 3.1 firmware (e.g. added to an NSArray). But Apple's code may have changed such that the -retain is no longer needed, and exposed the bug.