OK I'll try to explain. the reason you have to move the file is if you create a custom page that is to be used with a particular table then the correct behavoir is to move it to the ~/DynamicData/CustomPage/TableName/Page.aspx this is the default behavoir. DD routes always translate to the ~/DynamicData folder if there is a CustomePages folder for that table it will look there fist for the relavent page if not it will use a page from the PageTemplates folder.

OK so far.

Now if you have add a new route into the equasion it's still going to look at thing in the above way unless you make it clear in your route that the file is outside the ~/DynamicData folder.

See my example of running two models Dynamic Data – Registering Multiple Models and David Ebbo's Using Dynamic Data with multiple databases these may be of some help.

So if I had a page ~/Articles.aspx (in the root) of the site I would not need to provide a route to acces this file unless I wanted to have the paramter slug passed in as part of the url:

 ~/Articles.aspx?slug=10

So if I wanted to have a url like:

 ~/Articles.aspx/10

or

 ~/Articles/10

the I could add my own route handler, because if you look at a route: 

routes.Add(new DynamicDataRoute("{table}/{action}.aspx")
{
    Constraints = new RouteValueDictionary(new { action = "List|Details|Edit|Insert" }),
    Model = model
});

As you can see the route is a DynamicDataRoute.

For details non DD route see Mike Ormond's Getting ASP.NET Routing Up and Running - The Definitive Guide