title: NSOpenPanel's setDirectoryURL doesn't work
body: <p>I'm trying to use the new methods for NSOpenPanel and set its initial directory. The problem is that it only works at the first time and after that it just "remembers" the last selected folder, which I don't want. I have to use the depreciated runModalForDirectory:file: to make it work. It's less than ideal because it was deprecated at 10.6, but thankfully it still works on Lion.      </p>
  
  <p>My code is:</p>
  
  <pre><code>NSOpenPanel *panel = [NSOpenPanel openPanel];
  [panel setAllowedFileTypes:[NSArray arrayWithObjects: @"jpg",@"JPG",@"png", nil]];
  panel.canChooseDirectories = YES;
  panel.allowsMultipleSelection = YES;
  handler = ^(NSInteger result) {stuff};
  [panel setDirectoryURL:[NSURL URLWithString:@"/Library/Desktop Pictures"]];
  </code></pre>