Covariant object instantiation using reflection

It seems that i have found a strange bug in .NET-2.0/unity's .NET-2.0.

public class Test
{
    public interface ICovariant<out T>
    {
        T GetT();
    }

    public class Covariant<T>: ICovariant<T>
    {
        public T GetT()
        {
            throw new NotImplementedException();
        }
    }

    public interface IFoo
    {
    }

    public class Bar : IFoo
    {
    }

    public class CovariantHolder
    {
        public CovariantHolder(ICovariant<IFoo> covariant)
        {
        }
    }

    public class CovariantBar: Covariant<Bar>
    {
    }

    public static void Main(string[] args)
    {
        ICovariant<IFoo> foo = new Covariant<IFoo>();
        ICovariant<IFoo> foobar = new Covariant<Bar>();
        ICovariant<IFoo> bar = new CovariantBar();
        CovariantBar barbar = new CovariantBar();

        new CovariantHolder(foo);     // works
        new CovariantHolder(foobar);  // works
        new CovariantHolder(bar);     // works
        new CovariantHolder(barbar);  // works

        Console.WriteLine(typeof(ICovariant<IFoo>).IsAssignableFrom(typeof(Covariant<IFoo>))); // true;
        Console.WriteLine(typeof(ICovariant<IFoo>).IsAssignableFrom(typeof(Covariant<Bar>)));  // true;
        Console.WriteLine(typeof(ICovariant<IFoo>).IsAssignableFrom(typeof(CovariantBar)));    // false! what?;

        typeof(CovariantHolder).GetConstructors()[0].Invoke(new object[] {foo});      //works
        typeof(CovariantHolder).GetConstructors()[0].Invoke(new object[] {foobar});   //fails! WHAAT?
        typeof(CovariantHolder).GetConstructors()[0].Invoke(new object[] {bar});      //fails!
        typeof(CovariantHolder).GetConstructors()[0].Invoke(new object[] {barbar});   //fails!
    }
}

AFAIK, unity uses mono 2.0.50727.1433

Is there any way around it? Can I instatniate an object through reflection using covariant argument?