The .dll referenced below is in fact installed on my GAC. I can see it in in the GAC_MSIL directory. I added the file explicitly to the project and get the same result. Here is what is showing in the output window after I've added the file to the project, and then attempt to edit a ui map:
Error loading 'Telerik.WinControls.CodedUI.2010.dll' or one of its dependencies. Error details: System.TypeLoadException: Method 'GetValidSearchProperties' on type 'Telerik.WinControls.CodedUI.RadBaseTestControl' from assembly 'Telerik.WinControls.CodedUI.2010, Version=2013.1.220.40, Culture=neutral, PublicKeyToken=5bb2a467cbec794e' is overriding a method that is not visible from that assembly.