Mocks work when run in single test, but not in test list

Sorry for the bad subject

I have a test that uses TypeMock to intercept an SMS component. This works fine if I select to run only the one test. When I select two or more tests to run in the same test run, the test fails. The test in question is the ShouldAbortWithSMSNotificationIfReferredNumberAlreadyUsedInCurrentPromo test below.

I have tried to remove the transaction stuff, and I have tried to Sleep the test at various places to see if there is a lag in there somewhere, but with no luck. I would really appreciate any help to get this test to run fine alongside other tests.

Thanks,

Morten

      [TestMethod]
      public void ShouldAbortWithSMSNotificationIfReferredNumberAlreadyRegistered()
      {
         ReturnCodes expected = ReturnCodes.PhoneNumberAlreadyExists;
         MockManager.Init();
         Mock smsMock = MockManager.Mock(typeof(HSLSMSProvider), Constructor.NotMocked);
         smsMock.ExpectAndReturn("EnqueueMessage", ReturnCodes.OK, null).Args("+4741******-2", "The number +4741****** is already registered with ****** and is not eligible for the free €5.", "447797******", SMS.Providers.SMSSendPriority.Normal);

         FreeMoneySMSPromo promo = getPromo();
         ReturnCodes actual = promo.Process("PROMO 1 +4741******", "+4741******-2");

         Assert.AreEqual(expected, actual, "Result didn't match");
         MockManager.Verify();         
      }

      [TestMethod]
      public void ShouldAbortWithSMSNotificationIfReferredNumberAlreadyUsedInCurrentPromo()
      {
         ReturnCodes expected, actual;
         string referringMobileNumber = "+4741******";
         string referredMobileNumber = "+123456789";

         FreeMoneySMSPromo promo = getPromo();

         MockManager.Init();
         Mock smsMock = MockManager.Mock(typeof(HSLSMSProvider), Constructor.Mocked);
         smsMock.ExpectGet("SMSNumber", "4733******");
         smsMock.ExpectAndReturn("EnqueueMessage", ReturnCodes.OK, null).Args(referringMobileNumber, "The number +123456789 is already registered in this promotion and has already got the free €5.", "4733******", SMS.Providers.SMSSendPriority.Normal);

         using (TransactionScope scope = new TransactionScope(TransactionScopeOption.RequiresNew))
         {
            PromoDSTableAdapters.PromoPendingAccountsTableAdapter adapter = new PromoPendingAccountsTableAdapter();
            adapter.Insert(referredMobileNumber, (int?)promo.Settings.InitialFreeMoneyValue, 25, false, null);

            expected = ReturnCodes.PhoneNumberAlreadyRegisteredInCurrentPromo;
            actual = promo.Process(string.Format("PROMO 1 {0}", referredMobileNumber), referringMobileNumber);
         }

         Assert.AreEqual(expected, actual, "Result didn't match");
         MockManager.Verify();
      }