In the ORM designer, why aren't the server objects updated properly with the new changes?

Whenever I use the deisgner ORM in LinqToSql I have real problems trying to get the latest objects from the server explorer after I have updated them in the database.

For example, I have dragged and dropped a stored procedure to handle my inserts / updates, which creates a method to call. The problem is I need to go over and change one of the sp parameters in the database. When I drag sp back to the constructor, my new parameter is gone. Even after updating the server explorer object (db level), it still reverts to the previous settings. When I go through the options in the server explorer, it shows my new option, but doesn't bring it up when I drag and drop it.

The work around is to close all VS and then it works. This is obviously not ideal, so any help on this would be great.

thank.