sslzones is failing to redirect from https to http due to a bug inadvertently introduced in revision 17417, when the check to determine current access method (http or https) was moved out to ezsys.php. Result:

Fatal error: Call to a member function on a non-object in /eb/apps/ez/3.8/kernel/classes/ezsslzone.php on line 235
Fatal error: eZ publish did not finish its request

Patch:

Index: kernel/classes/ezsslzone.php
===================================================================
--- kernel/classes/ezsslzone.php        (revision 17453)
+++ kernel/classes/ezsslzone.php        (working copy)
@@ -231,6 +231,7 @@
         if ( $nowSSL && !$inSSL )
         {
             // switch to plain HTTP
+            $ini =& eZINI::instance();
             $host = $ini->variable( 'SiteSettings', 'SiteURL' );
             $sslZoneRedirectionURL = "http://" . $host  . $requestURI;
         }

I'm a little surprised by this, since a simple check to see if sslzones was worked as expected after this patch was applied should have revealed this bug.

Thanks
Matthew