after activated some block in sidebar-second styles are not applied from styles.css in sub-theme zen drupal 7

Also impossible to add some additional style to the sub-theme, but if deactivate sidebar-second everything works fine!
Any Idea?

solved!

Solution: take the file page.tpl.php and put into your template folder in sub-theme, then override the output blocks and classes for them it's will help in solving many unnecessary problems with HTML markup!

I mean that if sidebar-first it's not region-sidebar-first that has Zen Theme

as well as the author of this Theme decision for output

<div id="content">
<?php print render($page['content']); ?>
</div>

<?php
      // Render the sidebars to see if there's anything in them.
      $sidebar_first  = render($page['sidebar_first']);
      $sidebar_second = render($page['sidebar_second']);
    ?>

    <?php if ($sidebar_first || $sidebar_second): ?>
      <aside class="sidebars">
        <?php print $sidebar_first; ?>
        <?php print $sidebar_second; ?>
      </aside>
    <?php endif; ?>

there would be no problem, but client need to have website which adapted for Internet Explorer 6 - 8, and with this conclusion, we encounter the problem, the best way is to change like this:

<aside class="sidebar-left">
<?php print $sidebar_first; ?>
</aside>

<section id="content">
<?php print render($page['content']); ?>
</section>

<aside class="sidebar-right">
<?php print $sidebar_second; ?>
</aside>

in this case we have easier to work with the theme website