I'll add more here as I figure this out. How to get my asp.net app to see network resources.

I know the problem is that the web pages are being run as ASPNET account - non privileged machine.

Can tweak processModel attribute in machine.config, but it's machine wide change. (According to docs, can't override this in the web.config)

Here's an article about using a serviced component. I'm assuming this works, since it runs in COM+, which can be set to any identity.

15 Seconds : Accessing Shared Resources Using ASP.NET