title: Drupal Themes getting "unselected"
body: <p>Sometimes, at least 1 time a month +-, when I visit my site, there is no theme selected and I get a lot of error code.</p>
  
  <pre><code>Notice: Undefined index: highlighted em include() (linha 120 de /var/www/novoportal.faccat.br/htdocs/portal/modules/system/page.tpl.php).
      Notice: Undefined index: sidebar_first em include() (linha 132 de /var/www/novoportal.faccat.br/htdocs/portal/modules/system/page.tpl.php).
      Notice: Undefined index: sidebar_second em include() (linha 138 de /var/www/novoportal.faccat.br/htdocs/portal/modules/system/page.tpl.php).
      Notice: Undefined index: genesis em drupal_theme_initialize() (linha 100 de /var/www/novoportal.faccat.br/htdocs/portal/includes/theme.inc).
      Notice: Trying to get property of non-object em _drupal_theme_initialize() (linha 145 de /var/www/novoportal.faccat.br/htdocs/portal/includes/theme.inc).
      Notice: Trying to get property of non-object em _theme_load_registry() (linha 321 de /var/www/novoportal.faccat.br/htdocs/portal/includes/theme.inc).
      Notice: Undefined index: genesis em theme_get_setting() (linha 1316 de /var/www/novoportal.faccat.br/htdocs/portal/includes/theme.inc).
  </code></pre>
  
  <p>I always need to select the theme again and clear the cache.</p>
  
  <p>Also I used the Devel theme rebuild tool, but I keep getting these errors.</p>
  
  <p>Any Ideas?</p>