Cannot Run ASP.NET Web Service

I am having trouble running an ASP.NET Web Service application I just built. This web service references the MapPoint Web Service 3.5, which is referenced correctly by the project. I also checked the Web.config file, but could find no errors.

When I try to run the project in Debug mode (Debug -> Start) I get the following error:

Error occured while trying to run project: Unable to start debugging on the web server. Server side-error occurred on sending debug HTTP request.

Make sure the server is operating correctly. Verify there are no syntax errors in web.config by doing a Debug.Start Without Debugging. You may also want to refer to the ASP.NET and ATL Server debugging topic in the online documentation.

After receiving this error, the first thing I did was to check that I had correctly configured the virtual directory for that application. It looks fine.

I then tried to start the application without debugging, and got the following error:

Server Application Unavailable
The web application you are attempting to access on this web server is currently unavailable.  Please hit the "Refresh" button in your web browser to retry your request.

Any idea what's going on here?

- nhc