I just finished a credit card processing application for a payment processor
requiring the transaction data as an HTTP post. To avoid Sandbox issues, I
wrote a back end PHP program to relay the post, parse the result and return it
to the SWF on the client. The Flex program is loaded using the Zend Framework
Object Helper, htmlFlash. Zend Framework provides the template for the site
(Layout) - the Flex program runs in one section of the template.
The program worked with no issues on my developmennt system. When I pushed
(both programs) to the same demo server I started getting the "Security error
accessing url" message when the HTTPService is called. I am guessing the
message is because the SWF is invoked from the Zend Framework and does not
recognize that it is running in the same domain, but I am not certain. A
crossdomain.xml file on the server does not help.

How can I work around this? Would a proxy server in place of the PHP program
permit the HTTPService call? I am not sure which approach to take at this
point. Any help would be appreciated.

The error was not using "www" in the address. Although they both resolve to the same place, flash sees them as different domains. Thanks.