Problem with recursive fake on Generics

namespace TestProject1
{
    internal class MyItem
    {
        public MyItem(){}
    }

    internal class ClassToMock
    {
        public IList<MyItem> TheMyItemList { get; private set; }
        public IList<string> TheStringList { get; private set; }
    }

    internal class ClassUnderTest
    {
        public bool DoSomethingWithMyItemList(ClassToMock param)
        {
            return param.TheMyItemList.Count > 0; 
        }

        public bool DoSomethingWithStringList(ClassToMock param)
        {
            return param.TheStringList.Count > 0; 
        }
    }

    [TestClass]
    public class GenericsRecursiveFakeTest
    {
        [TestMethod]
        [Isolated]
        public void TestRecursiveFakeOnMyItemList()
        {
            ClassToMock fake = Isolate.Fake.Instance<ClassToMock>();

            ClassUnderTest target = new ClassUnderTest();

            Assert.IsFalse(target.DoSomethingWithMyItemList(fake));
        }

        [TestMethod]
        [Isolated]
        public void TestRecursiveFakeOnStringList()
        {
            ClassToMock fake = Isolate.Fake.Instance<ClassToMock>();

            ClassUnderTest target = new ClassUnderTest();

            Assert.IsFalse(target.DoSomethingWithStringList(fake));
        }
    }
}