title: In App Purchase's SKProductsRequest not working when App is already installed on the device
body: <p>I am having problems testing the In App Purchase feature. If I reinstall the app on a device that has already installed the app with a previous version, the SKProductsRequest returns a response only with an object on the invalidProductIdentifiers. If I delete the app from the device and then install the new version again, SKProductsRequest works fine.</p>
  
  <p>Any ideas?</p>
  
  <p>Thanks in advance.</p>
  
  <pre><code>- (void)requestProductData:(NSString *)aFeatureID {    
      SLLog(@"Products Request For: %@", aFeatureID);
      SKProductsRequest *request = [[SKProductsRequest alloc] initWithProductIdentifiers:[NSSet setWithObject:aFeatureID]];
      request.delegate = self;
      [request start];
  }
  
  - (void)productsRequest:(SKProductsRequest *)request didReceiveResponse:(SKProductsResponse *)response
  {
      if ([response.products count] &gt; 0) {        
          [self.purchasableObjects addObjectsFromArray:response.products];
  
  #ifndef NDEBUG  
          for(int i=0;i&lt;[self.purchasableObjects count];i++)
          {       
              SKProduct *product = [self.purchasableObjects objectAtIndex:i];
              SLLog(@"Feature: %@, Cost: %f, ID: %@",[product localizedTitle],
                    [[product price] doubleValue], [product productIdentifier]);
          }
  
          for(NSString *invalidProduct in response.invalidProductIdentifiers)
              SLLog(@"Problem in iTunes connect configuration for product: %@", invalidProduct);
  #endif  
          isProductsAvailable = YES;
      } else if ([response.invalidProductIdentifiers count] &gt; 0){
          SLLog(@"MKStoreManager-productsRequest empty results: %@", [response.invalidProductIdentifiers objectAtIndex:0]);
      }
      if([_delegate respondsToSelector:@selector(productFetchComplete)])
          [_delegate productFetchComplete];
      [request autorelease];
  }
  </code></pre>