The below error occurred when trying to build the csla.net 2.1.4 solution with visual studio 2005 on a machine that also had orcas installed:

"The application has failed to start because the application configuration is incorrect. Reinstalling the application may fix this problem"

I had previously downloaded the Orcas beta and installed on the same machine.  I ended up having to uninstall Orcas, then uninstall visual studio 2005, and re-install VS 2005.  After the re-install I was then able to build the csla solution.