追踪cocoa内存泄漏

我收到应用程序内存泄漏的报告,但我无法准确追踪到底发生了什么。我有一个函数,它取出旧视图并在新视图中交换。我没有使用NavController或任何@properties;我直接管理我的顶级窗口。

-(void)swapInView:(UIViewController*)newViewController
{
    [currentViewer.view removeFromSuperview];
    printf("Old viewController (%p) has count of %d; now releasing\n",
        currentViewer, [currentViewer retainCount]);
    [currentViewer release];
    currentViewer = 0;

    currentViewer = newViewController;
    [currentViewer retain];

    [mainWindow addSubview:currentViewer.view];
    [mainWindow bringSubviewToFront:currentViewer.view];
}

运行代码时,我显示当前视图控制器正在被释放,然后调用该视图控制器的dealloc方法。但是,仪器/泄漏仍然报告为泄漏。例如,我打印出以下内容:

Old viewController (0x119f80) has count of 1; now releasing
Deallocating WelcomeScreenViewController

MyViewController *theViewController = [[MyViewController alloc]
                                        initWithNibName:nil
                                                 bundle:nil];
[GameMaster swapInNewView:theViewController];
[theViewController release];

有人对如何追踪正在发生的事情有什么建议吗?我使用的是3.1.2SDK,但我在早期的SDK中也看到了这一点。