Form is not submitting after ajax callback
I think the problem is that you only return the another-field in the ajax callback.

You probably have to make a wrapper for the submit and the another-field.

So you willl have:

$form['ajax_wrapper'] = array(
  'submit' =&gt; array(
    // Submit button...
  ),
  'another-field' =&gt; array(
    // Another field...
  ),
);


And then return $form['ajax_wrapper'] in your ajax callback.
Make sure to use $form_state['rebuild'] = TRUE;