title: NSMutableArray count not updating with array
body: <p>I have an NSMutableArray which I initialized like this:</p>
  
  <pre><code>- (id)init
  {
      self = [super init];
      if (self) {
          playlist = [[NSMutableArray alloc] init];
      }
      return self;
  }
  </code></pre>
  
  <p>and am populating a table with it.  I have a method to count the number of items in the array:</p>
  
  <pre><code>- (NSUInteger)trackCount
  {
      tracks = [playlist count];
      NSLog(@"Number of tracks = %lx", tracks);
      return tracks;
  }
  </code></pre>
  
  <p>and I have a label bound to my appDelegate with the model key path <code>trackCount</code>, but the label doesn't update when tracks are added(nor does the log).  What am I doing wrong?? </p>
  
  <p>Would it make more sense and/or be easier to get a count of the rows in the table since they should always be the same number?</p>
  
  <p>Thanks</p>