Scott Hanselman presents a solution. "Can I mix Razor Views and WebForms Views in a single ASP.NET MVC application?", he asks. The answer is, "No, Yes, and Maybe, But It's Not Supported."
Anyways, the solutions is found on his blog.
In order to get the page title to work properly, I've done the following:
In the Controller:
ViewBag._Title = "Admin";
In the RazorView.aspx:
if (ViewBag._Title != null)
Page.Title = ViewBag._Title;