warning: preg_match() expects parameter 2 to be string, array given in bootstrap.inc on line 777

My apologize for my english.

I received this message in block section and I see the code say FIXME, so I want give a hand in this.

warning: preg_match() expects parameter 2 to be string, array given in D:\www\clientes2009\drupalargentina\v6\includes\bootstrap.inc on line 777.

/**
 * Implementation of after_build callback
 */
function drupal_tweaks_block_tweak($form, $form_state) {
  foreach ($form as $block_name => $block_data) {
    if (is_array($block_data)) {
      $module_name = $block_data['module']['#value'];
      $form[$block_name]['info']['#suffix'] .= ' ' . sprintf(t('(module: %s)'), $module_name);
      // FIXME: Why #suffix generates: warning: preg_match() expects parameter 2 to be string, array given in includes/bootstrap.inc on line 777 ?
    }
  }
  return $form;
}

Y changed for this and it look like

/**
 * Implementation of after_build callback
 */
function drupal_tweaks_block_tweak($form, $form_state) {
  foreach ($form as $block_name => $block_data) {
    if (is_array($block_data) && $block_data['module']['#value']) { //Not all the array is about modules blocks
      $module_name = $block_data['module']['#value'];
      $form[$block_name]['info']['#suffix'] .= ' ' . t('(module: %module)', array('%module' => $module_name)); //Minor change to t()
      // FIXME: Why #suffix generates: warning: preg_match() expects parameter 2 to be string, array given in includes/bootstrap.inc on line 777 ?
    }
  }
  return $form;
}

And it work like a charm