title: mutableCopy memory leak
body: <p>Can anyone shed some light as to why this use of mutableCopy is leaking memory?</p>
  
  <pre><code>- (id)objectInListAtIndex:(unsigned)theIndex {
         NSSortDescriptor *descriptor = [[[NSSortDescriptor alloc] initWithKey:@"noteNumber"  ascending:YES] autorelease];
         [list sortUsingDescriptors:[NSArray arrayWithObjects:descriptor,nil]];
         NSMutableArray *theArray = [list mutableCopy];
         NSDictionary *theDict = [theArray objectAtIndex:theIndex];
         return theDict;
   }
  </code></pre>