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="AIBablh" 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.