title: ASIFormDataRequest empty POST request
body: <p>I'm using ASIFormDataRequest to send multipart POST data to a server running nginx + php-fpm.</p>
  
  <pre><code>ASIFormDataRequest *request = [ASIFormDataRequest requestWithURL:url];
  [request setPostValue:sessionKey forKey:@"session"];
  [request setPostValue:secret forKey:@"secret"];
  [request setPostValue:@"test" forKey:@"description"];
  [request setFile:filePath forKey:@"image"]; 
  [request setTimeOutSeconds:120];
  [request setDelegate:self];
  [request startAsynchronous];
  </code></pre>
  
  <p>However, once in a while (occurs very randomly, hard to reproduce) an empty request reaches server, I'm using the same file for all tests. ASIHTTPRequest peforms requestFinished, like everything's ok.</p>
  
  <p>No server-side errors generated, I checked logs.</p>
  
  <p>Has anyone had this problem before?</p>