diff --git a/ISOv4Plugin/ExtensionMethods/ExtensionMethods.cs b/ISOv4Plugin/ExtensionMethods/ExtensionMethods.cs
index 66a5615..0949024 100644
--- a/ISOv4Plugin/ExtensionMethods/ExtensionMethods.cs
+++ b/ISOv4Plugin/ExtensionMethods/ExtensionMethods.cs
@@ -95,6 +95,13 @@ public static bool ReverseEquals(this string s1, string s2)
             return true;
         }
 
+        /// <summary>
+        /// Matches NumericRepresentation by code, accounting for null representation code
+        /// </summary>
+        public static bool ContainsCode(this ApplicationDataModel.Representations.Representation representation, string code)
+        {
+            return representation?.Code != null && representation.Code.Contains(code);
+        }
 
         /// <summary>
         /// Looks up unit, converts and loads representation
diff --git a/ISOv4Plugin/Mappers/PartfieldMapper.cs b/ISOv4Plugin/Mappers/PartfieldMapper.cs
index 8887a59..ffa211a 100644
--- a/ISOv4Plugin/Mappers/PartfieldMapper.cs
+++ b/ISOv4Plugin/Mappers/PartfieldMapper.cs
@@ -90,11 +90,16 @@ public ISOPartfield ExportField(Field adaptField)
 
             //Boundary
             PolygonMapper polygonMapper = new PolygonMapper(TaskDataMapper);
-            FieldBoundary boundary = DataModel.Catalog.FieldBoundaries.SingleOrDefault(b => b.FieldId == adaptField.Id.ReferenceId);
+
+            var boundaries = DataModel.Catalog.FieldBoundaries.Where(b => b.FieldId == adaptField.Id.ReferenceId).ToList();
+            var boundary = boundaries.FirstOrDefault(b=> b.Id.ReferenceId == adaptField.ActiveBoundaryId) ?? boundaries.FirstOrDefault();
             if (boundary != null)
             {
-                IEnumerable<ISOPolygon> isoPolygons = polygonMapper.ExportMultipolygon(boundary.SpatialData, ISOEnumerations.ISOPolygonType.PartfieldBoundary);
-                isoField.Polygons.AddRange(isoPolygons);
+                if (boundary.SpatialData != null)
+                {
+                    IEnumerable<ISOPolygon> isoPolygons = polygonMapper.ExportMultipolygon(boundary.SpatialData, ISOEnumerations.ISOPolygonType.PartfieldBoundary);
+                    isoField.Polygons.AddRange(isoPolygons);
+                }
             }
 
             //Guidance
diff --git a/ISOv4Plugin/Mappers/TimeLogMapper.cs b/ISOv4Plugin/Mappers/TimeLogMapper.cs
index f0eccf2..13a39bb 100644
--- a/ISOv4Plugin/Mappers/TimeLogMapper.cs
+++ b/ISOv4Plugin/Mappers/TimeLogMapper.cs
@@ -33,6 +33,8 @@ internal TimeLogMapper(TaskDataMapper taskDataMapper) : base(taskDataMapper, "TL
         {
         }
 
+        private static readonly DateTime _firstDayOf1980 = new DateTime(1980, 1, 1, 0, 0, 0, DateTimeKind.Local);
+
         #region Export
         private Dictionary<int, int> _dataLogValueOrdersByWorkingDataID;
         public IEnumerable<ISOTimeLog> ExportTimeLogs(IEnumerable<OperationData> operationDatas, string dataPath)
@@ -150,7 +152,6 @@ private class BinaryWriter
         {   // ATTENTION: CoordinateMultiplier and ZMultiplier also exist in Import\SpatialRecordMapper.cs!
             private const double CoordinateMultiplier = 0.0000001;
             private const double ZMultiplier = 0.001;   // In ISO the PositionUp value is specified in mm.
-            private readonly DateTime _januaryFirst1980 = new DateTime(1980, 1, 1);
 
             private readonly IEnumeratedValueMapper _enumeratedValueMapper;
             private readonly INumericValueMapper _numericValueMapper;
@@ -193,7 +194,7 @@ private void WriteSpatialRecord(SpatialRecord spatialRecord, List<WorkingData> m
                 var millisecondsSinceMidnight = (UInt32)new TimeSpan(0, spatialRecord.Timestamp.Hour, spatialRecord.Timestamp.Minute, spatialRecord.Timestamp.Second, spatialRecord.Timestamp.Millisecond).TotalMilliseconds;
                 memoryStream.Write(BitConverter.GetBytes(millisecondsSinceMidnight), 0, 4);
 
-                var daysSinceJanOne1980 = (UInt16)(spatialRecord.Timestamp - (_januaryFirst1980)).TotalDays;
+                var daysSinceJanOne1980 = (UInt16)(spatialRecord.Timestamp - _firstDayOf1980).TotalDays;
                 memoryStream.Write(BitConverter.GetBytes(daysSinceJanOne1980), 0, 2);
 
                 //Position
@@ -409,8 +410,7 @@ protected IEnumerable<OperationData> ImportTimeLog(ISOTask loggedTask, ISOTimeLo
                         operationData.GetDeviceElementUses = x => operationData.DeviceElementUses.Where(s => s.Depth == x).ToList();
                         operationData.PrescriptionId = prescriptionID;
                         operationData.OperationType = GetOperationTypeFromProductCategory(productIDs) ??
-                                                      GetOperationTypeFromWorkingDatas(workingDatas) ??
-                                                      GetOperationTypeFromLoggingDevices(time);
+                                                      OverrideOperationTypeFromWorkingDatas(GetOperationTypeFromLoggingDevices(time), workingDatas);
                         operationData.ProductIds = productIDs;
                         if (!useDeferredExecution)
                         {
@@ -428,22 +428,25 @@ protected IEnumerable<OperationData> ImportTimeLog(ISOTask loggedTask, ISOTimeLo
             return null;
         }
 
-        private OperationTypeEnum? GetOperationTypeFromWorkingDatas(List<WorkingData> workingDatas)
+        private OperationTypeEnum OverrideOperationTypeFromWorkingDatas(OperationTypeEnum deviceOperationType, List<WorkingData> workingDatas)
         {
             //Harvest/ForageHarvest omitted intentionally to be determined from machine type vs. working data
-            if (workingDatas.Any(w => w.Representation.Code.Contains("Seed")))
+            if (workingDatas.Any(w => w.Representation.ContainsCode("Seed")))
             {
                 return OperationTypeEnum.SowingAndPlanting;
             }
-            else if (workingDatas.Any(w => w.Representation.Code.Contains("Tillage")))
+            else if (workingDatas.Any(w => w.Representation.ContainsCode("Tillage")))
             {
                 return OperationTypeEnum.Tillage;
             }
-            if (workingDatas.Any(w => w.Representation.Code.Contains("AppRate")))
+            if (workingDatas.Any(w => w.Representation.ContainsCode("AppRate")))
             {
-                return OperationTypeEnum.Unknown; //We can't differentiate CropProtection from Fertilizing, but prefer unkonwn to letting implement type set to SowingAndPlanting
+                if (deviceOperationType != OperationTypeEnum.Fertilizing && deviceOperationType != OperationTypeEnum.CropProtection)
+                {
+                    return OperationTypeEnum.Unknown; //We can't differentiate CropProtection from Fertilizing, but prefer unknown to letting implement type set to SowingAndPlanting
+                }
             }
-            return null;
+            return deviceOperationType;
         }
 
         private List<List<string>> SplitElementsByProductProperties(Dictionary<string, List<ISOProductAllocation>> productAllocations, HashSet<string> loggedDeviceElementIds, ISODevice dvc)
@@ -682,9 +685,6 @@ private void AddProductAllocationsForDeviceElement(Dictionary<string, Dictionary
 
             switch (productCategories.FirstOrDefault())
             {
-                case CategoryEnum.Variety:
-                    return OperationTypeEnum.SowingAndPlanting;
-
                 case CategoryEnum.Fertilizer:
                 case CategoryEnum.NitrogenStabilizer:
                 case CategoryEnum.Manure:
@@ -722,7 +722,9 @@ private OperationTypeEnum GetOperationTypeFromLoggingDevices(ISOTime time)
                 }
             }
 
-            DeviceOperationType deviceType = representedTypes.FirstOrDefault(t => t.ClientNAMEMachineType >= 2 && t.ClientNAMEMachineType <= 11);
+            DeviceOperationType deviceType = representedTypes.FirstOrDefault(t => t.ClientNAMEMachineType >= 2 && t.ClientNAMEMachineType <= 11 &&
+                t.OperationType != OperationTypeEnum.Unknown);
+
             if (deviceType != null)
             {
                 //2-11 represent known types of operations
@@ -752,8 +754,6 @@ internal static Dictionary<byte, int> ReadImplementGeometryValues(IEnumerable<by
 
         protected class BinaryReader
         {
-            private static readonly DateTime _firstDayOf1980 = new DateTime(1980, 01, 01);
-
             public static Dictionary<byte, int> ReadImplementGeometryValues(string filePath, ISOTime templateTime, IEnumerable<byte> desiredDLVIndices, int version, IList<IError> errors)
             {
                 Dictionary<byte, int> output = new Dictionary<byte, int>();