When trying to run tests with MSTest I was getting the error: The location of the file or directory is not trusted.
- http://devdump.wordpress.com/2008/12/08/test-run-deployment-issue/
- http://social.msdn.microsoft.com/Forums/en-US/vststest/thread/1a9c13b3-e8b9-4619-9159-3edbfc67b8a9/
I tried unblocking the dll and rebuilding to no avail. The trick turned out to be that I needed to close and re-open the solution to make VS figure out the dlls were now unblocked.