asp.net Response.RedirectToRoute issue

In my global.ascx I have the routing setup: 

routeCollection.MapPageRoute("My Home Page", "myhomepage/{myid}", "~/MyHomePage.aspx");

I use Response.RedirectToRoute() with a parameter to open a page. I identified that in the following cases the redirect will fail:

• The parameter is not given. e.g. Response.RedirectToRoute("My Home Page");
• The parameter as null value. e.g. Response.RedirectToRoute("My Home Page", new {myid = null});
• The parameter as null value. e.g. Response.RedirectToRoute("My Home Page", new {myid = string.empty});

Apparently you MUST give a non-empty value to the parameter.