I have developed a site using ASP.NET 3.5, located within a virtual directory that is on a server running on IIS v5.1. Just this afternoon as I was fixing something on the development site, I started getting a 404 error ("The resource cannot be found") after clicking on one of the links within an ASP.NET Menu control. I know why I'm getting the 404, and that's because I keep getting redirected to a Default.aspx page in the directory directly above the virtual directory. But I don't understand why this would be happening if the URL is pointing to a valid page.
I have checked and double-checked the URL to make sure that I didn't misspell anything (I'm using the relative path, so the URL is something like "~/pgName.aspx"). I've tried creating a new ASPX page and copying/pasting the contents of the other page, but I get the same 404 error. In addition, I cannot get Intellisense to work after pasting the code (the controls don't show up in the drop down, either).