I have a Visual Studio 2010 MVC 3 application with unit tests projects in it. I have a TFS 2008 build definition to build the solution.
On the build agent i have got
The switches are added because MSTest is trying to publish the test results to the server so that you can see the information in the build log in team build explorer, as well as in the cube for reporting, etc.
Assuming you installed Team Explorer 2010 when you installed VS2010 Professional you should be able to publish the test results (unless the licensing requires premium or ultimate - I can't remember). It might be worth reinstalling and reapplying the service pack to see if that fixes the problem.