TestInitialize method is never executed

The method Initialize() is never executed. I dont't understand why every methods are in public. MyContext is null in the test method. I tried 2 runners and I get the same behavior (Devexpress/CodeRush and Testdriven)

Here the code

[TestClass]
public class MyTests
{
    public MyContext MyContext;
    public MyRepository repo;

    [TestInitialize]
    public void Initialize()
    {
        MyContext = new MyContext();
        repo = new MyRepository(MyContext);
    }

    [TestMethod]
    public void MyTestMethod()
    {
        using (IUnitOfWork unitOfWork = new UnitOfWork(MyContext))
        {
            var myObject = new MyObject { 
            };

            repo.Add(myObject);

            unitOfWork.Commit();
        }
    }
}