iOS - 在购买苹果服务器后从Apple服务器下载

在iOS6中，我们有新功能将内容放置在Apple服务器上，以便在成功购买后可以下载内容并正确使用该内容。

我可以成功进行购买，当下载内容时，它停止在75％。
我尝试使用不同的购买和不同的内容放在苹果服务器上。但是它停止在75％...不知道为什么。
我正在使用以下代理方法来跟踪下载进度：

In iOS6, we have new feature to place the content on Apple Server so that after successful purchase, the content can be downloaded and use it appropriately.
I'm able to make the purchase successfully and when downloading the content, it stops at 75%.
I tried with different purchases and different content placed on apple server. but it stops at 75%... dont know why. I'm using the following delegate method to track the download progress:

-(void)paymentQueue:(SKPaymentQueue *)queue updatedDownloads:(NSArray *)downloads
{
    for (SKDownload *download in downloads)
    {
        switch (download.downloadState) {
            case SKDownloadStateActive:
                NSLog(@"Download progress = %f and Download time: %f", download.progress, download.timeRemaining);
                break;
            case SKDownloadStateFinished:
                NSLog(@"%@",download.contentURL);
                break;
            default:
                break;
        }
    }
}

它从未达到SKDownloadStateFinished

有任何人面临类似的问题。如果是，分辨率是多少？

Its never reaching "SKDownloadStateFinished"
Has any one faced similar issue. if yes, what's the resolution?