cocos2d-iphone - CCLabelBMFont が setString で update で失敗する

Question

CCLabelBMFont をアニメーションで表示しようとすると、一部のユーザーでランダムに失敗する Cocos2d アプリがあります。どのテスト デバイスでも問題を再現できません。845 行目で失敗しているように見えるので、mmemory が不足しているのではないかと思っています。cocos2d v2.0.0 を使用しています。

for (TileBlockModel* tile in [matchInfo tiles]) {
    if (tile.matchScore > 0 && tile.spriteObject != nil) {
        NSString* str = [NSString stringWithFormat:@"%d",tile.matchScore];
        CCLabelBMFont* label = [CCLabelBMFont labelWithString:str fntFile:@"8-WHITE NUMBERS.fnt"];
        label.position = ((CCNode*)tile.spriteObject).position;
        label.scale = label.scale * fontMultiplier;
        label.zOrder = TILE_BLOCK_SCORE_Z_LEVEL;
        [gameGrid addChild:label];
        CCActionInterval* action = [CCSequence actions:
                            [CCMoveBy actionWithDuration:.4 position:ccp(0, ((CCNode*)tile.spriteObject).boundingBox.size.height)],
                                    [CCCallBlockN actionWithBlock:^(CCNode* node){
            [node removeFromParentAndCleanup:YES];
        }],
                            nil];
        [label runAction:[CCSpeedPointer actionWithAction:action speed_:globalGameSpeed]];

    }

}

クラッシュログ

0     vault2richesiphone                    0x00078a02 -[CCLabelBMFont setString:updateLabel:] (CCLabelBMFont.m:845)
1     vault2richesiphone                    0x00078d29 -[CCLabelBMFont setFntFile:] (CCLabelBMFont.m:921)
2     vault2richesiphone                    0x00077f1d -[CCLabelBMFont updateLabel] (CCLabelBMFont.m:622)
3     vault2richesiphone                    0x000b58b3 -[gameViewController displayMatchScore:] (gameViewController.m:1100)
4     vault2richesiphone                    0x000b68ab -[gameViewController animateColumnDrop:andRow:andOffset:animationId:] (gameViewController.m:1226)
5     vault2richesiphone                    0x0006755d -[CCRepeat stop] (CCActionInterval.m:307)
6     vault2richesiphone                    0x0006c4bf -[CCProgressTo startWithTarget:] (CCActionProgressTimer.m:53)
7     vault2richesiphone                    0x0008ca59 +[CCShaderCache sharedShaderCache] (CCShaderCache.m:41)
8     vault2richesiphone                    0x000a070d -[CCDirectorIOS setProjection:] (CCDirectorIOS.m:217)
9     QuartzCore                            0x3581c7a9 _ZN2CA7Display11DisplayLink8dispatchEyy + 161
10   QuartzCore                             0x3581c701 _ZN2CA7Display16IOMFBDisplayLink8callbackEP21__IOMobileFramebufferyyyPv + 65
11   IOMobileFramebuffer                    0x37a98fd7 IOMobileFramebufferVsyncNotifyFunc + 155
12   IOKit                                  0x3480f5ad IODispatchCalloutFromCFMessage + 193
13   CoreFoundation                         0x33bf188b __CFMachPortPerform + 119
14   CoreFoundation                         0x33bfc3e7 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 35
15   CoreFoundation                         0x33bfc38b __CFRunLoopDoSource1 + 139
16   CoreFoundation                         0x33bfb20f __CFRunLoopRun + 1383
17   CoreFoundation                         0x33b6e23d CFRunLoopRunSpecific + 357
18   CoreFoundation                         0x33b6e0c9 CFRunLoopRunInMode + 105
19   GraphicsServices                       0x3774d33b GSEventRunModal + 75
20   UIKit                                  0x35a8a2b9 UIApplicationMain + 1121