I'm working on a series of projects, all of which have some fundamental things in common.  Those common elements are abstracted into a form which the projects inheret from.  I started a new project, and added ParentForm.cs to it via the Solution Explorer.  (Right Click -> Add -> Existing Item)  If I right click on ParentForm.cs, and click "View Designer," everything works just fine.  If I right click on ChildForm.cs, and click "View Designer," I get the following error: "An exception occured while trying to create an instance of <namespace>.ParentForm.  The exception was 'Object reference not set to an instance of an object."  Oddly enough, the ChildForm project compiles /and/ executes just fine.  I'm stumped.  Suggestions?