As of 1.8.6, the order can be changed in: /qa-include/app/page.php
Move this block:
// Only the 'level' permission error prevents the menu option being shown - others reported on /qa-include/pages/ask.php
if (qa_opt('nav_ask') && qa_user_maximum_permit_error('permit_post_q') != 'level') {
$qa_content['navigation']['main']['ask'] = array(
'url' => qa_path_html('ask', (qa_using_categories() && strlen($lastcategoryid)) ? array('cat' => $lastcategoryid) : null),
'label' => qa_lang_html('main/nav_ask'),
);
}
above
if (qa_opt('nav_activity')) {....