Index: DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/DamMacroStabilityCommon/MStabXmlDoc.cs
===================================================================
diff -u -r1060 -r1105
--- DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/DamMacroStabilityCommon/MStabXmlDoc.cs	(.../MStabXmlDoc.cs)	(revision 1060)
+++ DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/DamMacroStabilityCommon/MStabXmlDoc.cs	(.../MStabXmlDoc.cs)	(revision 1105)
@@ -62,13 +62,13 @@
         /// <param name="subSoilScenario"></param>
         /// <param name="mstabDesignEmbankment"></param>
         /// <param name="requiredSafetyFactor"></param>
-        /// <param name="failureMechanismParametersMStab"></param>
+        /// <param name="inputfailureMechanismParametersMStab"></param>
         /// <param name="errorMessages"></param>
         /// <returns></returns>
         public static XDocument CreateMStabXmlDoc(string mstabProjectFilename, DesignScenario scenario, 
             SoilGeometryProbability subSoilScenario, 
             MStabDesignEmbankment mstabDesignEmbankment, 
-            double requiredSafetyFactor, FailureMechanismParametersMStab failureMechanismParametersMStab,
+            double requiredSafetyFactor, FailureMechanismParametersMStab inputFailureMechanismParametersMStab,
             out List<LogMessage> errorMessages)
         {
 
@@ -77,6 +77,7 @@
             var soilGeometry2DName = subSoilScenario.FullStiFileName;
 
             ConsistencyCheck(scenario, profile1D);
+            var failureMechanismParametersMStab = inputFailureMechanismParametersMStab.Clone();
 
             failureMechanismParametersMStab.Location = scenario.Location;
             if (profile1D != null)
@@ -154,11 +155,9 @@
                 scenario.Location.StabilityOptions.StabilityZoneType;
 
             // Zonestype is ZoneAreas; TODO: Combine with code in StabilityCalculation
-            var dikeTopAtPolder = scenario.Location.SurfaceLine.CharacteristicPoints.GetGeometryPoint(CharacteristicPointType.DikeTopAtPolder);
-            if (
-                failureMechanismParametersMStab.MStabParameters.CalculationOptions.ZonesType.Equals(
-                    MStabZonesType.ZoneAreas))
+            if (failureMechanismParametersMStab.MStabParameters.CalculationOptions.ZonesType.Equals(MStabZonesType.ZoneAreas))
             {
+                var dikeTopAtPolder = scenario.Location.SurfaceLine.CharacteristicPoints.GetGeometryPoint(CharacteristicPointType.DikeTopAtPolder);
                 double? dikeTableHeight = scenario.DikeTableHeight ?? scenario.Location.SurfaceLine.GetDefaultDikeTableHeight();
                 if (!dikeTableHeight.HasValue)
                     throw new MStabXmlDocException("Surface line has no dike table height.");