[flexcoders] Caching problem

[Alex]

Hi there!

  I have an xml file that needs to be loaded eventually using a 
URLRequest. I'm trying to avoid loading a cached file using these 
headers:

        urlRequest.requestHeaders.push(new URLRequestHeader("Cache-
Control", "no-cache, no-store, max-age=0, must-revalidate"));
        urlRequest.requestHeaders.push(new URLRequestHeader
("Expires", "Fri, 30 Oct 1998 14:19:41 GMT"));
        urlRequest.requestHeaders.push(new URLRequestHeader
("Pragma", "no-cache"));                                

It works ok in firefox and IE6.0.2900, but I still obtain a cached file 
in IE6.0.3790+ and IE7.

Do I need to add any more headers? or what's the problem here?

Thanks in advance