web.config and configuaration xmlns= line

[dm1608]

I've noticed that when I compile my ASP.NET 2.0 app that I'm now getting a
bunch of warnings "Could not find schema information for the attribute
'xxx'. Where xxx = almost every custom attribute I've added to override
what is in Machine.Config.

The xmlns= at top of file points to
http://schemas.microsoft.com/.NetConfiguration/v2.0.

I get a 404 error when trying to get to this page... although
http://schemas.microsoft.com works.

Does anyone know if Microsoft changed something already?