CFHTTP problem with Host Headers

I am trying to post a form on a windows server using cfhttp.

The website relies on host headers to work properly (there are many sites on the server), but cfhttp posts appear not to send the required header information, returning a "No websites are configured" error message.

I've tried sending header info with <cfhttpparam type="header" name="host" value="www.mydomain.tld"> and it hasn't worked.

It may be important to know that the domain name is local only and relies on an entry in the hosts file, both on the browser machine and the server machine.

I have recently reconfigured the web server.  Previously, each site had its own IP address, but now they are all the same and using host headers.  Before, when each site had a unique IP, the cfhttp posts worked fine.

Is there a way to get them working in the host header configuration?

Thanks for replies.

- Don