Michel in this case you better ask Rick Strahl I donn't kcnow WWC do you have any thing that indicates the hit is not to be cached?
This is what response.expires=-1 does.

>>But the XMLHTTP object is doing a get to an asp page or not?
>>This case the client is the XMLHTP object but is a client as the internet explorer.
>
>No, we're not calling an ASP page. We're calling a WWC transaction.