title: UITextField keyboard doesn't appear
body: <p>I have a very simple screen with an UITextField with the default configuration, nothing special.<br><br>
  When I touch the UITextField, the keyboard doesn't pops up.<br><br>
   I haven't any custom control, behavior or anything else, just that, but it doesnt'work.<br><br>
  I've done this in previous apps iPhone/iPad apps already on the AppStore but i can't figure out what's going wrong here.</p>
  
  <p>The UITextField is created in Interface Builder, in the nib file.<br>
  I've been doing some research and i added an IBAction in the UIViewController for UItextField TouchDown event and the IBOutlet for the UITexField.<br>
  In the first line of the code i added:<br></p>
  
  <pre><code>[textFild becomeFirstResponder];
  </code></pre>
  
  <p>That's the default behavior of the UITextField, when you touch it, it becomes the first responder asking the system to show the keyboard.<br>
  I debugged it and it runs that line, but the keyboard still doesn't shows up.<br>
  Thanks in advance.</p>