Loading XML files in Flash over an SSL Connection in Internet Explorer fails if the "Pragma: no-cache" or "Cache-Control: no-cache"
HTTP headers are set in the server’s response.
If you want to keep the browser from caching your dynamic content you’ll have to use other means.
One of the possible solutions that uses headers to prevent caching without causing errors in IE are:
"Cache-Control: no-store" and/or "Expires: Thu, 01 Jan 1970 01:00:00 GMT"
More info on this issue:
http://robsondesign.com/blog/index.php/2008/08/30/ie-ssl-xml-https-swf-doa/
