title: I cannot create NSImage with imageNamed but initWithContentsOfFile
body: <p>With the following code:</p>
  
  <pre><code>NSString *imageString = [[NSBundle mainBundle] pathForResource:@"logo64x64" ofType:@"png"];
  NSImage *testImage = [[NSImage imageNamed:@"logo64X64"] retain];
  NSImage *testImage2 = [[NSImage alloc] initWithContentsOfFile:imageString];
  </code></pre>
  
  <p><code>testImage</code> is nil but <code>testImage2</code> is a <code>NSImage</code> instance. I don't know what's wrong with the code. I'm sure I can find <code>logo64x64.png</code> and <code>logo64x64@2x.png</code> in the resource directory in the bundle. I've also tried <code>imageNamed:@"logo64X64.png"</code> but still getting nil.</p>
  
  <p>Anyone can help?</p>