linq-to-sql stored-procedures asp.net-3.5

LINQ to SQL -- Can't modify return type of stored procedure

When I drag a particular stored procedure into the VS 2008 dbml designer, it shows up with Return Type set to "none", and it's read only so I can't change it. The designer code shows it as returning an int, and if I change that manually, it just gets undone on the next build.

But with another (nearly identical) stored procedure, I can change the return type just fine (from "Auto Generated Type" to what I want.)

I've run into this problem on two separate machines. Any idea what's going on?

Here's the stored procedure that works:

USE [studio]
GO
/****** Object:  StoredProcedure [dbo].[GetCourseAnnouncements]    Script Date: 05/29/2009 09:44:51 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER OFF
GO
CREATE PROCEDURE [dbo].[GetCourseAnnouncements]
    @course int
AS
SELECT * FROM Announcements WHERE Announcements.course = @course
RETURN

And this one doesn't:

USE [studio]
GO
/****** Object:  StoredProcedure [dbo].[GetCourseAssignments]    Script Date: 05/29/2009 09:45:32 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER OFF
GO
CREATE PROCEDURE [dbo].[GetCourseAssignments]
    @course int
AS
SELECT * FROM Assignments WHERE Assignments.course = @course ORDER BY date_due ASC
RETURN

Solution

Okay, I found the problem... kind of. I had changed the name of the table "Assignments" and forgot to update the stored procudure, so the DBML designer was confused. BUT even after I updated the stored procedure, deleted it from the DBML designer and readded it, it wasn't working!

This is nearly the same problem discussed here: http://forums.asp.net/t/1231821.aspx.

It only worked when I deleted the stored procedure from the database and recreated it, and deleted it from the DBML designer, recompiled, restarted Visual Studio, and added it again. This is the second time I've run into "refresh" problems with the Visual Studio DBML designer...