I have a test project using MbUnit and TestDriven.Net.
If I right-click on an individual test method and say "Run Tests" the test runs successfully. Same thing if I click on a file name in the solution explorer.
However, if I right click and say run tests on the project or the solution, TestDriven.Net reports "0 Passed, 0 Failed, 0 Skipped."
I have other similar projects that work just fine, and yes, the classes are labeled [TestFixture] and the methods are labeled [Test].