SKStoreProductViewController title and right nav bar button in iOS7

Question

I used SKStoreProductViewController to open App Store in my own app. This is the part of my implementation.

NLStoreProductViewController *storeController = [[NLStoreProductViewController alloc] init];
[storeController setTitle:storeControllerTitle];

NSString* appUrlString = gExtAppStoreUrl[app];
NSString* appIdNumbersOnly = [appUrlString substringFromIndex:([appUrlString rangeOfString:@"id"].location) + [@"id" length]];
NSDictionary *productParameters = @{SKStoreProductParameterITunesItemIdentifier :appIdNumbersOnly};

[storeController loadProductWithParameters:productParameters completionBlock:^(BOOL result, NSError *error) {
    if (result) {
        [currentViewController presentViewController:storeController animated:YES completion:nil];
    }
 }];

But title text and the navigation right bar button is not shown when I run it in iOS7. Those are shown and working in iOS6.

I searched for this issue on google, Stackoverflow, and many other sites, but I found there's no talking about it. Has anybody know about this issue?