Kamocsay Lajos: how to debug EXC_BAD_ACCESS on iPhone

Itt van az egesz, de roviden a lenyeg:

If you set the NSZombiEnabled environment variable, the Objective C runtime will leave a dummy object behind for every deallocated object. When the zombie object is called, execution stops and you can see the message that was sent to the object and the call stack that tells you where the message came from (it doesn’t tell you where you over released the object, but knowing where the object is called from should get you pretty close to the problem.)