You have the `#disabled` property set on your submit element. Drupal's form API does not process the input for any element, including submit buttons, if the `#disabled` property is set on the server side.

If you're interested in the code behind this, the decisions are made in the [`_form_builder_handle_input_element()`][1] function in the `includes/form.inc` file of your Drupal installation.

If you want the submit button to be disabled by default for client-side purposes (i.e. you'll be enabling it through JS based on some action taken by the user) you would be better off setting the `disabled` attribute directly on the element, as Drupal pays no attention to this when processing the form:

    $form['submit'] = array(
      '#type' => 'submit',
      '#value' => t('Submit'),
      '#attributes' => array(
        'style' => "padding: 0 10px;",
        'disabled' => 'disabled'
      )
    );

[1]: http://api.drupal.org/api/drupal/includes!form.inc/function/_form_builder_handle_input_element/7