Replaced form AJAX not working
You don't post the code performing the actual AJAX request, so I have to assume it's directly calling an URL returning just the rendered version of the textfield wrapper with id "panorama_titulo_div".

Since this is sort of side-stepping Drupal's own AJAX functionality (which operates on a per-form basis, initiated by the "#ajax" key being present on certain elements), you'll need to perform some steps manually.

First you need to tell elements in the form that they are about to be removed using Drupal.detachBehaviors($('#panorama_titulo_div').get(0), Drupal.settings, 'unload');

Then you replace the form like you already do.

Finally, you need to re-attach all the JavaScript behaviors since any script operating on the elements in the replaced form won't have any references to the new elements.

Drupal.attachBehaviors($('#panorama_titulo_div').get(0));
This is where Drupal would normally pass the settings received together with other commands returned from an AJAX operation. We don't have that here, and it's not that important since we're not adding/removing elements or otherwise alter the DOM structure and won't introduce any new scrips.
Just to be sure every behaviors works, Drupal calls Drupal.attachBehaviors() again with the entire form as the context argument. You may want to do that too if you notice some things aren't working. It's a safe operation since all behaviors are required to keep track of whether they're already attached or not (often done using jQuery's .once() method.