[kall]

PHP Code:

if (!in_array($vbulletin->userinfo['userid'], preg_split('#\s*,\s*#s', $vbulletin->config['SpecialUsers']['superadministrators'], -1, PREG_SPLIT_NO_EMPTY)))
{
        print_cp_message('You have to be a super administrator to read private messages, this can be set within config.php');
} 


Not by the looks of the code, unless that 'regular user' happens to also be a Super Admin.