title: Invalid Argument exception when using setText on UILabel
body: <p>Im going crazy trying to debug a problem, where I get an exception</p>
  
  <pre><code>*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[NSCFString setText:]: unrecognized selector sent to instance 0x5799c90'
  </code></pre>
  
  <p>the code that is throwing it is:</p>
  
  <pre><code>- (void)request:(ASIHTTPRequest *)request didReceiveBytes:(long long)bytes
  {
  
      for(int index=0;index&lt;[pendingDownloadsArray count];index++)
      {
          if ([request isEqual:[[pendingDownloadsArray objectAtIndex:index]objectForKey:@"request"]])
          {
              NSNumber *x = [[pendingDownloadsArray objectAtIndex:index] objectForKey:@"completed"];
  
              float newCompleted = [x floatValue]+(float)bytes;
  //          x+=(float)bytes;
                          NSLog(@"Completed: %fKb",newCompleted/1024);
              x = [NSNumber numberWithFloat:newCompleted];
  
              [[pendingDownloadsArray objectAtIndex:index] setObject:x forKey:@"completed"];
              float progress = newCompleted / (float)request.contentLength;
  
              //Dont try to get cell if the table is showing something else.
              if(self.selectedSegment ==0)
              {
                  DownloadsCustomCell *cell =(DownloadsCustomCell*) [downloadsTableView cellForRowAtIndexPath:[NSIndexPath indexPathForRow:index inSection:0]];
                  [cell.downloadProgressView setProgress:progress];
                  NSString *progressLabelText = [NSString stringWithFormat:@"%.2f percent (%.2fKb / %.2fKb)",progress*100,
                                             newCompleted/1024,((float)request.contentLength/1024)];
                  NSLog(@"%@",progressLabelText);
                  UILabel *label = cell.downloadProgressLabel;
                  label.text = progressLabelText;
              }
  
          }
  
      }
  }
  </code></pre>
  
  <p>its throwing the exception on the last line. (i did not have the unnecessary 'label' at first... so its existence is a mark of how confused i am.
  either problem is something I didnt know, or im doing something incredibly stupid that I am not able to spot. 
  Can you please help me assign that NSString to that UILabel?
  (PS: i checked, downloadsProgressLabel IS A UILABEL.)</p>