title: NUnit generated Mock Repository returns the same object in different test cases
body: <p>Hi I am just starting off with Test Driven Development. I have a code where I have two test cases</p>
  
  <pre><code>     [Test, Order(3)]
      public void Should_Not_Create_ServiceAccountTaxCode_If_BillType_Is_Not_RateReady()
      {
          //ARRANGE
          var customerDetailsViewForBillTYpeRateReady = new CustomerTaxDetailsView
          {
              BillType = (int)BillTypes.BillReady
          };
  
          _repository.Stub(x =&gt; x.GetCustomerDetailsForTaxes(Arg&lt;int&gt;.Is.Anything)).Return(dict.Dequeue());
  
  
          //ACT
          var result = _concern.PopulateServiceAccountWithTaxDetails(Arg&lt;int&gt;.Is.Anything);
  
      [Test, Order(4)]
      public void Should_Create_ServiceAccountTaxCode_If_BillType_Is_RateReady()
      {
          //ARRANGE
          const int serviceAccountId = 1;
          var customerDetailsView = new CustomerTaxDetailsView
          {
              BillType = (int)BillTypes.RateReady,
              ServiceTypeId = (int)ServiceTypes.Electric
          };
         _repository.Stub(x =&gt; x.GetCustomerDetailsForTaxes(serviceAccountId))
              .Return(customerDetailsView).Repeat.Once();
          var result = _concern.PopulateServiceAccountWithTaxDetails(serviceAccountId);
  </code></pre>
  
  <p>And I am generating the mock using following syntax in the </p>
  
  <pre><code>    [OneTimeSetUp]
      public void Initialize()
      {
       _repository = MockRepository.GenerateMock&lt;IServiceAccountTaxCodeRepository&gt;();
  </code></pre>
  
  <p>The only problem is that in the second test case also my result object is customerDetailsViewForBillTYpeRateReady from first test case. Why is this happenning. And if i run these tests independently then everything is passed. Any help would be appreciated..</p>