title: writeImageDataToSavedPhotosAlbum Slows Dramatically After A Few Uses
body: <p>I save images to the iPhone's photo album using the api "writeImageDataToSavedPhotosAlbum". However, after several uses (such as 4), it begins to take approximately twice as long each time to save.</p>
  
  <p>I have created a test method to reproduce it, where it saves the exact same image each time. The method is as follows:</p>
  
  <pre><code>-(IBAction)testButton {
      NSData *data = [NSData dataWithContentsOfFile:[[self photosDirectory] stringByAppendingPathComponent:[[self contentsOfPhotoDirectory] objectAtIndex:0]]];
      ALAssetsLibrary *al = [[ALAssetsLibrary alloc] init];
      __block NSDate *date = [[NSDate date] retain];
      [al writeImageDataToSavedPhotosAlbum:data metadata:nil completionBlock:^(NSURL *assetURL, NSError *error) {
          NSLog(@"Saving Time: %g", [[NSDate date] timeIntervalSinceDate:date]);
          [date release];
      }];
      [al release];
  }
  </code></pre>
  
  <p>On a freshly restarted iPhone 4, I get the following save times. </p>
  
  <pre><code>2011-06-01 21:23:13.641 myapp[95:707] Saving Time: 5.30819
  2011-06-01 21:23:17.101 myapp[95:707] Saving Time: 1.5311
  2011-06-01 21:23:21.916 myapp[95:707] Saving Time: 2.52412
  2011-06-01 21:23:25.974 myapp[95:707] Saving Time: 2.85623
  2011-06-01 21:23:32.275 myapp[95:707] Saving Time: 4.93484
  2011-06-01 21:23:42.024 myapp[95:707] Saving Time: 7.93288
  2011-06-01 21:24:00.317 myapp[95:707] Saving Time: 15.8561
  2011-06-01 21:24:33.199 myapp[95:707] Saving Time: 29.7571
  </code></pre>
  
  <p>What is wrong?</p>