title: selectall uitextfield does not always select all
body: <pre><code>- (void)textFieldDidBeginEditing:(UITextField *)textField {
      [textField selectAll:self];
  }
  - (BOOL)textFieldShouldReturn:(UITextField *)textField {
      [textField resignFirstResponder];
      return YES;    
  }
  </code></pre>
  
  <p>In the above, the textField selects correctly but when I return from the keyboard and tap the textField for a second time consecutively, it does not select the text.  If I do not pick it consecutively or if I deselect the text before returning from the keyboard, the next focus of that textField selects the text correctly.</p>
  
  <p>How can I select the text in the abovementioned case?</p>