You just need to call repositoryIntance.ReplayAll(); before calling
tested method.
[Test]
public void this_test_fails()
{
var repositoryIntance = new MockRepository();
var test= repositoryIntance.Stub<ITest>();
test.Stub(t => t.GetInt()).Return(1);
//move to act mode
repositoryIntance.ReplayAll();
var id = test.GetInt();
Assert.That(id, Is.EqualTo(1)); //Fails id is 0!
}