Although the variable $_SERVER['HTTPS'] should be empty when it isn't a HTTPS request, a few webserver set the value to 'off'. The PHP reference manual ([http://at.php.net/manual/en/…]) mentions IIS and I encountered the problem with Abyss webserver. If the value is set to 'off', Action_Helper_Redirector redirects the request to https which is wrong. Therefore the Action_Helper_Redirector should be changed in function *_redirect($url)* from

$proto = (empty($_SERVER['HTTPS'])) ? 'http' : 'https';

to

$proto = ((empty($_SERVER['HTTPS'])) || (strcasecmp($_SERVER['HTTPS'],'off') == 0)) ? 'http' : 'https';