ReportViewer and HTTP 401

I have read a million documents on this question and I still don't get it. I would greatly appreciate any insights.

I start a new WebSite. I put these specs in web.config:

<authentication mode="Windows"/>

<identity impersonate="true" userName="AIB\ablh" password="blah" />

<authorization> <deny users="?"/> </authorization>

I put a ReportViewer control on my only page.

I set the URL and the ReportName and run the application which returns HTTP 401, authorization error. What else do I have to do to make this little demonstration work?

I have read entries about credentials, about delegation, about application pools, about just about everything.

Isn't this just supposed to work? This works without difficulty on a Windows form.

Much thanks.

Is your web application and Report Server on the same IIS box?

Do your virtual directories (Reports / ReportServer) have Anonymous checked or unchecked?

Does this happen if you run the web application on the server or just on a client (not the web server)?

Are the credentials you provide in the web.config domain or a machine specific windows account?