MVC3 Routing Working 1 Direction Only - asp.net

Question

I am working on an ASP.NET mvc 3 site that contains several project entities, and then each project has several associated subpages, each that works with a component of the project.
So for instance, I could have a project with several photos, milestones, user info, etc. I have a Project Index view, as well as a Project Home which links to several component pages. Most of the components have two views, Index, and Edit/View.
So I set up a route for the edits and views. Note that my route is in an AREA called ProjectManagement
context.MapRoute(
"ProjectManagement_ProjectPageSingle",
"ProjectManagement/{controller}/{action}/{projectNumber}/{projectChildId}",
new { controller = "Project", action = "Home" }
);
and my controller actions all look similar to this:
public ActionResult Edit(string projectNumber, string projectChildId)
This works well and good when I type in the URL directly in the browser. For instance:
~/ProjectManagement/Milestone/Edit/39999P110175/1
however, when I generate an action link using:
<a href="#Url.Action("Edit", new { projectNumber = Model.Project.ProjectNumber, projectChildId = entry.Id})">
the action URL ends up looking like this:
~/ProjectManagement/Milestone/Edit/39999P110175?projectChildId=1
So the route sorta works...but the action link generator doesn't? Not sure where to go from here. Any advice would be much appreciated.
Note that the same thing occurs while using #Html.ActionLink instead of #Url.Action.
Thanks!

Answer 1

You don't seem to have specified the area name:
#Url.Action(
"Edit",
new {
projectNumber = Model.Project.ProjectNumber,
projectChildId = entry.Id,
area = "ProjectManagement"
}
)
Also make sure that there aren't any other routes that might conflict with this one in your area registration which should look like this:
public override void RegisterArea(AreaRegistrationContext context)
{
context.MapRoute(
"ProjectManagement_default",
"ProjectManagement/{controller}/{action}/{projectNumber}/{projectChildId}",
new { controller = "Project", action = "Home" }
);
}

Answer 2

Thanks to Michael for the response. Here's the answer for others.
I had:
context.MapRoute(
"ProjectManagement_ProjectPage",
"ProjectManagement/{controller}/{action}/{projectNumber}",
new { controller = "Project", action = "Home"}
);
///more routes
context.MapRoute(
"ProjectManagement_ProjectPageSingle",
"ProjectManagement/{controller}/{action}/{projectNumber}/{projectChildId}",
new { controller = "Project", action = "Home" }
);
The URL matched the ProjectPage route as well, so it took that one first. Had to flip the order, so the more specific route came first.
Thanks.