title: -[NSConcreteMutableData release]: message sent to deallocated instance
body: <p>I am facing a problem of -[NSConcreteMutableData release]: message sent to deallocated instance, i have attached my sample code as well.</p>
  
  <pre><code>- (IBAction)uploadImage {
  
  NSString *urlString = @"http://192.168.1.108/iphoneimages/uploadfile.php?userid=1&amp;charid=23&amp;msgid=3";
  
  
  //if(FALSE)
  for (int i=0; i&lt;[imgArray count]; i++) {
  
      // setting up the request object now
      NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
      [request setURL:[NSURL URLWithString:urlString]];
      [request setHTTPMethod:@"POST"];
  
      /*
      add some header info now
      we always need a boundary when we post a file
      also we need to set the content type
  
      You might want to generate a random boundary.. this is just the same 
      as my output from wireshark on a valid html post
   */
      NSString *boundary = [NSString stringWithString:@"---------------------------14737809831466499882746641449"];
      NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@",boundary];
      [request addValue:contentType forHTTPHeaderField: @"Content-Type"];
  
      /*
       now lets create the body of the post
       */
      NSMutableData *body = [[NSMutableData data] autorelease];
  
      NSString *str = [NSString stringWithFormat:@"Content-Disposition: form-data; name=\"userfile\"; filename=\"ipodfile%d.jpg\"\r\n",i];
  
      [body appendData:[[NSString stringWithFormat:@"\r\n--%@\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];    
      [body appendData:[[NSString stringWithString:str] dataUsingEncoding:NSUTF8StringEncoding]];
      [body appendData:[[NSString stringWithString:@"Content-Type: application/octet-stream\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
  
  
      NSData *imageData = UIImageJPEGRepresentation([imgArray objectAtIndex:i], 90);
      [body appendData:[NSData dataWithData:imageData]];
  
  
      [body appendData:[[NSString stringWithFormat:@"\r\n--%@--\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];
      // setting the body of the post to the reqeust
      [request setHTTPBody:body];
  
      // now lets make the connection to the web
      [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
      //NSString *returnString = [[NSString alloc] initWithData:returnData encoding:NSUTF8StringEncoding];
      //NSLog(@"%@",returnString);
      [imageData release];
  
      [request release];
      //[body release];
  }
  }
  </code></pre>
  
  <p>It successfully upload the images to the folder and there is no any error in the execution but when it complete it process and try to go back it give error -[NSConcreteMutableData release]: message sent to deallocated instance</p>
  
  <p>Please help me out.</p>
  
  <p>Thanks</p>