Hi Richard,
the given code was just a sample to simplify the question. In "reality" both classes, tested and second class are in a seperate assembly (but the same). The effect nevertheless was the same, the constructor of second class which needs some services not available at testing time is called. I solved the problem by mocking the second class as well, so I've a workaround for me.
May the reason for the problem in the above code be the same as for "real life" code as well? I don't know how C# calls static constructors. Perhaps there are other constellations that lead to the same problem even if the code is in a different assembly (and the two classes in different C# files)?
Thanks again for your quick and adjuvant reply,
Michael