Cocos2D crashing on iPhone immediately but not in simulator

I'm trying to test a Cocos2D app on an iPhone, and get this crash that I copied from the console:

    cocos2d: CCSpriteFrameCache: Trying to use file 'heroTestSheet.png' as texture
    cocos2d: CCTexture2D. Can't create Texture. UIImage is nil
    cocos2d: Couldn't add image:heroTestSheet.png in CCTextureCache
    cocos2d: CCSpriteFrameCache: Couldn't load texture
    cocos2d: CCTexture2D. Can't create Texture. UIImage is nil
    cocos2d: Couldn't add image:heroTestSheet.png in CCTextureCache
    cocos2d: CCSpriteFrameCache: Frame 'heroFrame1.png' not found
    *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[NSMutableArray insertObject:atIndex:]: attempt to insert nil object at 0'
    *** Call stack at first throw:
    (
0   CoreFoundation                      0x3759dc7b __exceptionPreprocess + 114
1   libobjc.A.dylib                     0x32d9bee8 objc_exception_throw + 40
2   CoreFoundation                      0x3752a951 -[__NSArrayM insertObject:atIndex:] + 136
3   CoreFoundation                      0x3752a8bf -[__NSArrayM addObject:] + 34
4   cocosTests                          0x0000ce28 -[HeroClass init] + 1544
5   cocosTests                          0x0000304c -[DebugZoneLayer init] + 860
6   cocosTests                          0x00074e04 +[CCNode node] + 76
7   cocosTests                          0x0000c4e4 -[DebugZoneScene init] + 244
8   cocosTests                          0x00074e04 +[CCNode node] + 76
9   cocosTests                          0x0000c390 +[DebugZoneScene scene] + 100
10  cocosTests                          0x00002540 -[cocosTestsAppDelegate applicationDidFinishLaunching:] + 1028
11  UIKit                               0x3592502c -[UIApplication _callInitializationDelegatesForURL:payload:suspended:] + 1200
12  UIKit                               0x3591ea78 -[UIApplication _runWithURL:payload:launchOrientation:statusBarStyle:statusBarHidden:] + 396
13  UIKit                               0x358d82e4 -[UIApplication handleEvent:withNewEvent:] + 1476
14  UIKit                               0x358d7b1c -[UIApplication sendEvent:] + 68
15  UIKit                               0x358d73b4 _UIApplicationHandleEvent + 6824
16  GraphicsServices                    0x33e77c88 PurpleEventCallback + 1048
17  CoreFoundation                      0x3752f5cb __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 28
18  CoreFoundation                      0x3752f589 __CFRunLoopDoSource1 + 164
19  CoreFoundation                      0x37521835 __CFRunLoopRun + 580
20  CoreFoundation                      0x3752150b CFRunLoopRunSpecific + 226
21  CoreFoundation                      0x37521419 CFRunLoopRunInMode + 60
22  UIKit                               0x3591d554 -[UIApplication _run] + 548
23  UIKit                               0x3591a558 UIApplicationMain + 972
24  cocosTests                          0x000020c4 main + 100
25  cocosTests                          0x0000205c start + 40
    )
    terminate called after throwing an instance of 'NSException'
    Program received signal:  “SIGABRT”.
    warning: Unable to read symbols for /Developer/Platforms/iPhoneOS.platform/DeviceSupport/4.2.1 (8C148)/Symbols/Developer/usr/lib/libXcodeDebuggerSupport.dylib (file not found).

Running it in the simulator runs fine, but I still get this message in the console when it starts up "CCSpriteFrameCache: Trying to use file 'heroTestSheet.png' as texture"

I suspect that's where the problem starts. Maybe I'm just understanding how my code for my hero sprite subclass should be written. I thought heroTestSheet.png was the texture it was relying on to split up into other images referencing the plist.

Here's my init in my hero subclass:

    -(id) init{
    self = [super init];
    if (!self) {
        return nil;
    }

    _collisWidthFromCtr  = 16;
    _collisHeightFromCtr = 16;

    _collisPushPointsNums = 5;

    _travelRectCenterPoints = [[NSMutableArray alloc] init];

    _collisPushPoints = [[NSMutableArray alloc] init];

    [_collisPushPoints insertObject:[NSValue valueWithCGPoint:CGPointMake( _collisWidthFromCtr, _collisHeightFromCtr)] atIndex:0];
    [_collisPushPoints insertObject:[NSValue valueWithCGPoint:CGPointMake( _collisWidthFromCtr,                    0)] atIndex:1];
    [_collisPushPoints insertObject:[NSValue valueWithCGPoint:CGPointMake( _collisWidthFromCtr,-_collisHeightFromCtr)] atIndex:2];
    [_collisPushPoints insertObject:[NSValue valueWithCGPoint:CGPointMake( 0,                   _collisHeightFromCtr)] atIndex:3];
    [_collisPushPoints insertObject:[NSValue valueWithCGPoint:CGPointMake(-_collisWidthFromCtr, _collisHeightFromCtr)] atIndex:4];

    _rectCheckRes = 32;

    _speed = 8;

    [[CCSpriteFrameCache sharedSpriteFrameCache] addSpriteFramesWithFile:@"heroTestSheet.plist"];

    _heroSpriteSheet = [CCSpriteBatchNode batchNodeWithFile:@"heroTestSheet.png"];

    //[self addChild:_heroSpriteSheet];

    NSMutableArray *heroSpriteFlyAnimFrames = [NSMutableArray array];
    for(int i = 1; i <= 2; ++i) {
        [heroSpriteFlyAnimFrames addObject:
         [[CCSpriteFrameCache sharedSpriteFrameCache] spriteFrameByName:
          [NSString stringWithFormat:@"heroFrame%d.png", i]]];
    }

    CCAnimation *heroSpriteFlyAnim = [CCAnimation animationWithFrames:heroSpriteFlyAnimFrames delay:0.03f];

    _heroSprite = [CCSprite spriteWithSpriteFrameName:@"heroFrame1.png"];  

    _heroSpriteFlyAction = [CCRepeatForever actionWithAction:[CCAnimate actionWithAnimation:heroSpriteFlyAnim restoreOriginalFrame:NO]];
    [_heroSprite runAction:_heroSpriteFlyAction];

    [_heroSpriteSheet addChild:_heroSprite];

    return self;
}

Please excuse me if I'm being unclear, so let me know any other info I need to provide. Just posting this for now because I don't know where else to start to solve it and what other info I should provide, and it might be obvious to some other cocos devs whats wrong from what I posted. Thanks

The simulator can be more forgiving than the device. Double check that your file name really is "heroTestSheet.png" and not "HeroTestSheet.png" for example. It is case sensitive on your device.