MVC Routing Not Working In Virtual Directory

I have an asp.net mvc 2 app (using .net 4.0) that isn't routing correctly when hosted in a virtual directory. I have the following simple routing rule:

routes.MapRoute(
"Default", // Route name
"{action}", // URL with parameters
new { controller = "accounts" } // Parameter defaults
);

I'm trying to resolve [URL]. Where "accounts" is a virtual directory. If I put the app in the root of an IIS website it routes fine for [URL], but if I put the app in a virtual directory I get 404 errors. I've debugged and it is executing global.asax and configuring routing when in the vdir. Is there something special I need to do for routing in a virtual directory? FYI. I'm using a vdir because the root has wordpress in it. one more thing is that if I specify a default action in parameter defaults, it will execute the default action/controller, but it never matches anything else.