anchor.diff:  
       //TODO: look for a way to remove the helper functions
       static let currentFrameworkDirectory = System.Runtime.InteropServices.RuntimeEnvironment.GetRuntimeDirectory()
  -    static let Net20AssemExPath () =
  -        let key = @"SOFTWARE\Microsoft\.NETFramework\v2.0.50727\AssemblyFoldersEx\Public Assemblies (Common Files)"
  -        let hklm = Registry.LocalMachine
  -        let rkey = hklm.OpenSubKey(key)
  -        let path = rkey.GetValue("") :?> string
  -        if String.IsNullOrEmpty(path) then None
  -        else Some(path)
   
       /////////////////////////////////
       // project helpers
       static let SaveProject(project : UnitTestingFSharpProjectNode) =
           project.Save(null, 1, 0u) |> ignore
  -
  -    static let DefaultBuildActionOfFilename(filename) : Salsa.BuildAction = 
  -        match Path.GetExtension(filename) with 
  -        | ".fsx" -> Salsa.BuildAction.None
  -        | ".resx"
  -        | ".resources" -> Salsa.BuildAction.EmbeddedResource
  -        | _ -> Salsa.BuildAction.Compile            
   
       static let GetReferenceContainerNode(project : ProjectNode) =
           let l = new List<ReferenceContainerNode>()
  
positive.code: open System.Reflection
  
  open NUnit.Framework
  open Salsa
  open UnitTests.TestLib.Utils.Asserts
  open UnitTests.TestLib.Utils.FilesystemHelpers
  open UnitTests.TestLib.ProjectSystem
  
  open Microsoft.VisualStudio
  open Microsoft.VisualStudio.FSharp.ProjectSystem
  open Microsoft.VisualStudio.Shell.Interop
  open Microsoft.Win32
  open System.Xml.Linq
  
  [<TestFixture>][<Category "ProjectSystem">]
  
negative.code:             Assert.Fail("adding a duplicate reference should have failed")
          with e ->
              TheTests.HelpfulAssertMatches ' ' "A reference to '.*' could not be added. A reference to the component '.*' already exists in the project." e.Message
  
      /// Create a dummy project named 'Test', build it, and then call k with the full path to the resulting exe
      member public this.CreateDummyTestProjectBuildItAndDo(k : string -> unit) =
  