Uninstalled Visual_WebGui_SDK_3.5_6.2.0a, Unistalled Microsoft Silverlight Tools for Visual Studio 2008 Beta 2 and uninstalled Microsoft Silverlight 2 Beta 2.

Installed Microsoft Silverlight 2 RTW, Installed Microsoft Silverlight Tools for Visual Studio 2008 SP1 (RC1) and reinstalled Visual_WebGui_SDK_3.5_6.2.0a.

Now when building a project with silverlight receive a warning "Cound not resolve silverlight assembly named 'System.Windows.Controls.Extended'." When the .swgx is run the screen is blank (white);