Installing UCMA SDK requires .NET 3.5 Framework error message

When trying to install the latest UCMA SDK for OCS 2007 R2 (http://www.microsoft.com/downloads/details.aspx?familyid=B20967B1-6CF5-4A4B-B7AE-622653AC929F&displaylang=en), I got the error message stating that the installation could not continue because of a missing .NET 3.5 Framework.

Strange, because I program in Visual Studio 2008 and certainly had installed the latest version of the framework.

However, I also installed the Visual Studio 2010 RC recently including the .NET 4.0 Framework. Just uninstall this version, install the UCMA SDK and reinstall the .NET 4.0 (http://www.microsoft.com/downloads/details.aspx?FamilyID=a9ef9a95-58d2-4e51-a4b7-bea3cc6962cb&displaylang=en) Framework to get it to work.