Do NOT remove the reference to System.Core from your VS2010 Project

One of the things I routinely do when adding a new class library project, is remove all references and just add them back in as I need them. That is NOT a good idea for Visual Studio 2010. When I DID need System.Core, and went to add it back, this is what I got: "A reference to 'System.Core' could not be added. This component is automatically referenced..."After some Googling I found this article