Custom control toolbox installation for different .NET Framework versions

Hi All,

Why if I compile the following code with Target Framework as .NET Framework 4.0 I can install the .NET Framework 4.0 version of my custom control while if I compile it with Target Framework as .NET Framework 2.0 I can only install .NET Framework 2.0 version of my custom control.

I would like to use the same .NET Framework 2.0 utility to install both versions (Fx20 and Fx40) of my custom control. What should I change?

Thanks,

Alberto

        /// <summary>
        /// Performs an installation of toolbox items.
        /// </summary>
        private void Install(DTE visualStudio)
        {
            // Progress has occurred
            OnProgressChanged();

            // Locate the project template necessary to access the Toolbox
            string tmpFile = Path.GetFileNameWithoutExtension(Path.GetTempFileName());
            string tmpDir = string.Format("{0}{1}", Path.GetTempPath(), tmpFile);
            Solution2 solution = visualStudio.Solution as Solution2;
            string templatePath = solution.GetProjectTemplate(_ProjectTemplate, "CSharp");

            // Progress has occurred
            OnProgressChanged();

            // Create a temporary project to get at the Toolbox for that platform
            Project proj = solution.AddFromTemplate(templatePath, tmpDir, tmpFile, false);

            // Progress has occurred
            OnProgressChanged();

            // Get a handle to the toolbox itself
            EnvDTE.Window window = visualStudio.Windows.Item(EnvDTE.Constants.vsWindowKindToolbox);
            EnvDTE.ToolBox toolbox = (EnvDTE.ToolBox)window.Object;

            // Check to see if the Toolbox tab already exists
            ToolBoxTab CurrentTab = null;
            foreach (ToolBoxTab tab in toolbox.ToolBoxTabs)
            {
                // Is there a match?
                if (tab.Name == _ToolboxTab)
                {
                    // Yes.
                    CurrentTab = tab;
                    break;
                }
            }

            // Is there an existing tab?
            if (CurrentTab == null)
            {
                // No.  Create a new one!
                CurrentTab = toolbox.ToolBoxTabs.Add(_ToolboxTab);
            }

            // Progress has occurred
            OnProgressChanged();

            // Select the Toolbox tab
            CurrentTab.Activate();

            // And add the control to it
            CurrentTab.ToolBoxItems.Add("MyUserControl", _AssemblyPath, vsToolBoxItemFormat.vsToolBoxItemFormatDotNETComponent);

            // Progress has occurred
            OnProgressChanged();
        }