For to make sure, update to latest upload.
Run 'sh /script/fix-chownchmod; sh /script/fixweb; sh /script/restart-services'. You not enable 'secondary php', all .htaccess inside '/home/kloxo/httpd/webmail' must be without 'AddHandler x-httpd-php52 .php'.
Also try, change disable 'secondary php' and change back to enable.