Using ASP.NET - Editor keeps looking for PHP

What am I doing wrong? My FCKEditor keeps trying to access PHP files when I'm using the ASP.NET version of the editor. I even tried doing Classic ASP but when I click on the file manager to link to a file, it bombs out because the PHP isn't being processed correctly.

What config file do I need to change in order to force the editor to use the ASP or ASP.NET files?

Thanks!