I guess the Telerik WebUI VSExtensions 2011.1.315 got upgraded on your machine through the Visual Studio Online Gallery and you don't have a full installation of RadControls.
There are two options to upgrade RadControls:
- Download the RadControls for ASP.NET AJAX Q1 2011 SP1 installer (released yesterday, Apr. 13th) and run it;
- Run Visual Studio, create a RadControls project and use the Download Latest Version button to acquire the latest hotfix version to your machine.
The difference between the two approaches is that the installer contains the documentation as well as refreshed Live Examples.
Let me know if that helps.
the Telerik team