title: NSFileManager fileExistsAtPath only works for absolute paths
body: <p>I have a bunch of customer images (named [code].png) in a folder, but some customers do not have images, so I'd like to display a placeholder.</p>
  
  <p>I'm checking the existence of the image [code].png, and if it exists I display that one, else I display the placeholder.  However, fileExistsAtPath <em>always</em> returns false, even for images that exist.</p>
  
  <pre><code>NSFileManager *m    = [NSFileManager defaultManager];
  NSString *imagePath = [NSString stringWithFormat:@"%@.png",code];
  if ([m fileExistsAtPath:imagePath])
      self.detailViewController.imageFrame.image = [UIImage imageNamed:[NSString stringWithFormat:@"%@.png",code]];
  else
      self.detailViewController.imageFrame.image = [UIImage imageNamed:@"customer_large.png"];
  </code></pre>
  
  <p>This always displays customer_large.</p>
  
  <p>However, if I change the imagePath to an absolute path to the image <em>and leave the displayed image as a relative filename</em>, the boolean works correctly, <em>and the image displayed works as well</em>.</p>
  
  <p>This proves that the filename I am checking for does exist, as the image displays, but I'm obviously missing something in terms of fileExistsAtPath as it returns false when the program has proven the file to exist.</p>