Very cool. Looking over the code, I learned a few little tricks I didn’t know about.
I hadn’t realized that XmlDocument can load a remote URL, though it’s right there in the SDK docs. I seem to remember in the Aggie source code that they have a special wrapper to handle the Http fetch.
A little fooling around reveals that XmlDocument.Load() doesn’t handle 302 redirects gracefully. In fact, the resulting exception puts my HttpApplication into a permanently broken state until I restart the application 😦
Update 2003-04-22: Simon is unable to reproduce this behavior. Neither am I when I point my code at his pingback url.
As best I can tell, the problem only arises when both documents—the code making the request and the code issuing the 302–are running on the same IIS 5.1 instance.