Not your usual "Failed to start monitoring changes to [path] error

[Guest]

I have a web application that is throwing a common error, but in a very
unusual state. I'm specifically receiving the following error:
"Failed to start monitoring changes to 'd:\inetpub\wwwroot'."

The error is being thrown on one of the <%@ Register %> tags at the top of
the ASX page that's registering ASP.NET user controls ASCX we wrote.

What's unusual is that this machine only has a single volume (c:\). We
built this app in a development environment (laptop) which only had one
volume. Then we deployed through our build/test/staging/production
environments that all have our apps installed to d:\.

In an effort to stand up a new test box, my infrastructure people backed up
the IIS metabase and all codebase from the existing server and restored it
onto the new test server. The new server only has one volume (c:\) so
everything was placed there. After updating a few virtual
directories/applications to point to the correct path, I'm still seeing this
error.

I've double checked all web.config's to make sure nothing is pointing to a
specific path. Even the <%@ Register %> tag uses a "~/" to obtain the
working application path. I'm certain no hard coded paths are in the code...
if it were, the same code would have shown these errors when we moved from
DEV -> build/test/staging/production. I've also double checked every single
web application and virtual directory listed within the virtual server in IIS
to make sure they are pointing to valid references.

Ideas?