tabs style zen primary links problem

i try using this, change the zen primary menu likes on this thread
http://zugec.com/drupal/using-css-tab-designer-with-zen-theme

and add extra php on template.php

function zen_links($links) {
  if (!count($links)) {
    return '';
  }
  $level_tmp = explode('-', key($links));
  $level = $level_tmp[0];
  $output = "<ul class=\"links-$level\">\n";
  foreach ($links as $index => $link) {
    $output .= '<li';
    if (stristr($index, 'active')) {
      $output .= ' class="active"';
    }
    $output .= ">". l($link['title'], $link['href'], $link['attributes'], $link['query'], $link['fragment']) ."</li>\n";
  }
  $output .= '</ul>';

  return $output;
}

but, the result is it affect the other ul and li list items style,
like read more links, and in category links..
how can i solve this only using this as primary menu ?

thanks