Use drupal_set_message($repeat = FALSE)

The module uses code like drupal_set_message(t('APC is not enabled. It is <strong>not</strong> safe to enable summary logging to the database on live sites.'), 'error');; it would be better to use drupal_set_message(t('APC is not enabled. It is <strong>not</strong> safe to enable summary logging to the database on live sites.'), 'error', FALSE); to avoid to have the same message printed twice on the same page.