Mock a call to a static func in a class with a static c'tor

Hi All,

I'm relatively new to the TypeMock scene and I am having an issue Isolating a call to a static function in a class that has a static constructor. I'm fairly certain it's due to the static c'tor. The error I get is as follows, the particularly interesting spots are:

TypeMock.CannotEvaluateWhileRecordingException:
*** Cannot evaluate methods inside a recording block

and a little bit further down:
System.TypeInitializationException: The type initializer for 'Comkt.Web.Estara.EstaraHelper' threw an exception.
at Comkt.Web.Estara.EstaraHelper.GetCoreJS(EstaraPageCategory templateCategory)

TypeMock.CannotEvaluateWhileRecordingException: 
*** Cannot evaluate methods inside a recording block
at TypeMock.MockManager.a(String A_0, String A_1, Object A_2, Object A_3, Boolean A_4, Object[] A_5)
at TypeMock.InternalMockManager.getReturn(Object that, String typeName, String methodName, Object methodParameters, Boolean isInjected, Object p1)
at NetUtils.Legacy.LegacyUtil.GetConfig(String configName) in Util.cs: line 13
at Comkt.Web.Estara.EstaraHelper..cctor() in EstaraHelper.cs: line 35 
System.TypeInitializationException: The type initializer for 'Comkt.Web.Estara.EstaraHelper' threw an exception.
at Comkt.Web.Estara.EstaraHelper.GetCoreJS(EstaraPageCategory templateCategory)
at CMWebTests.Estara.BaseEstaraControllerTests.<GetEstaraCoreScript_Test>b__0() in BaseEstaraControllerTests.cs: line 89
at TypeMock.MockManager.a(String A_0, String A_1, Object A_2, Object A_3, Boolean A_4, Object[] A_5)
at TypeMock.InternalMockManager.getReturn(Object that, String typeName, String methodName, Object methodParameters, Boolean isInjected)
at CMWebTests.Estara.BaseEstaraControllerTests.GetEstaraCoreScript_Test() in BaseEstaraControllerTests.cs: line 78

Pertinents parts of class I'd like to mock calls to/from:

public class EstaraHelper {
   private static bool estaraIntegrationOn;
   private static string coreScriptUrl;
   private static string accountId;
   private static string buttonImageUrl;

   private static bool EstaraIntegrationOn {
      get { return estaraIntegrationOn; }
   }

   private static string CoreScriptUrl {
      get { return coreScriptUrl;   }
   }
   
   private static string AccountId {
      get { return accountId;   }
   }

   private static string ButtonImageUrl {
      get { return buttonImageUrl; }
   }

   static EstaraHelper() {
      string estaraIntegrationSetting = LegacyUtil.GetConfig("EstaraIntegrationOn"); 
      estaraIntegrationOn = estaraIntegrationSetting.ToLower().Equals("y");   
      accountId = LegacyUtil.GetRequiredConfig("EstaraAccountId");
      coreScriptUrl = LegacyUtil.GetRequiredConfig("EstaraCoreScriptURL");
      buttonImageUrl = LegacyUtil.GetRequiredConfig("EstaraPttButtonUrl");
   }


   ...

   //FUNC I'D LIKE TO FORCE THE RESULTS FROM
   public static string GetCoreJS(EstaraPageCategory templateCategory) {
      if (EstaraIntegrationOn) {            
         return PutTogetherCoreJS(templateCategory);
      }
      else {
         return String.Empty;
      }
   }
}

A simple NUnit test causing the error:

[Test, Isolated]
public void GetEstaraCoreScript_Test() {
   const string testCoreJsScript = "My Test Core JS Script";
   const long testPageViewEventIt = 9999;
   const EstaraPageCategory testPageCategory = EstaraPageCategory.AutoAspx;

   MockEstaraController mockEstaraController = new MockEstaraController(testPageCategory, testPageViewEventIt);
   Isolate.WhenCalled(() => EstaraHelper.GetCoreJS(EstaraPageCategory.AutoAspx)).WillReturn(testCoreJsScript);


   //function under test
   string result = mockEstaraController.GetEstaraCoreScript();

   Assert.AreEqual(testCoreJsScript, result);
}

The static c'tor in question is relatively benign, just setting some private class variables from the configuration system, I could change the public accessors to them to lazy initialize, but I'd rather not have to change the class under test.

Any thoughts?

Thanks in advance for the help!