diff --git a/src/main/java/seng302/App.java b/src/main/java/seng302/App.java
index 28d7e923..c7a764c0 100644
--- a/src/main/java/seng302/App.java
+++ b/src/main/java/seng302/App.java
@@ -63,7 +63,7 @@ public class App extends Application {
         //Change the StreamReceiver in this else block to change the default data source.
         else{
 //            sr = new StreamReceiver("localhost", 4949, "RaceStream");
-            sr = new StreamReceiver("csse-s302staff.canterbury.ac.nz", 4941, "RaceStream");
+            sr = new StreamReceiver("localhost", 4949, "RaceStream");
         }
 
         sr.start();
diff --git a/src/main/java/seng302/controllers/CanvasController.java b/src/main/java/seng302/controllers/CanvasController.java
index 40642f41..43c4b40a 100644
--- a/src/main/java/seng302/controllers/CanvasController.java
+++ b/src/main/java/seng302/controllers/CanvasController.java
@@ -255,7 +255,7 @@ public class CanvasController {
 
     private void initializeMarks() {
         Map<Integer, Mark> allMarks = StreamParser.getXmlObject().getRaceXML().getCompoundMarks();
-
+        System.out.println(allMarks);
         for (Mark mark : allMarks.values()) {
             if (mark.getMarkType() == MarkType.SINGLE_MARK) {
                 SingleMark sMark = (SingleMark) mark;
@@ -270,6 +270,7 @@ public class CanvasController {
             }
         }
         group.getChildren().addAll(markGroups);
+        System.out.println(group.getChildren());
     }
 
     class ResizableCanvas extends Canvas {
diff --git a/src/main/java/seng302/models/mark/GateMark.java b/src/main/java/seng302/models/mark/GateMark.java
index ffcf2b51..79943114 100644
--- a/src/main/java/seng302/models/mark/GateMark.java
+++ b/src/main/java/seng302/models/mark/GateMark.java
@@ -39,12 +39,10 @@ public class GateMark extends Mark {
     }
 
     public double getLatitude(){
-        //return (this.getSingleMark1().getLatitude() + this.getSingleMark2().getLatitude()) / 2;
         return (this.getSingleMark1().getLatitude());
     }
 
     public double getLongitude(){
-        //return (this.getSingleMark1().getLongitude() + this.getSingleMark2().getLongitude()) / 2;
         return (this.getSingleMark1().getLongitude());
     }
 
diff --git a/src/main/java/seng302/models/mark/MarkGroup.java b/src/main/java/seng302/models/mark/MarkGroup.java
index ecb0cdc7..c87ae174 100644
--- a/src/main/java/seng302/models/mark/MarkGroup.java
+++ b/src/main/java/seng302/models/mark/MarkGroup.java
@@ -90,6 +90,7 @@ public class MarkGroup extends Group {
     {
         if (mainMark.getMarkType() == MarkType.SINGLE_MARK) {
             Circle markCircle = (Circle) super.getChildren().get(0);
+
             markCircle.setCenterX(x);
             markCircle.setCenterY(y);
         } else {
diff --git a/src/main/java/seng302/models/mark/SingleMark.java b/src/main/java/seng302/models/mark/SingleMark.java
index d4b4f3f2..9239552a 100644
--- a/src/main/java/seng302/models/mark/SingleMark.java
+++ b/src/main/java/seng302/models/mark/SingleMark.java
@@ -11,7 +11,6 @@ public class SingleMark extends Mark {
     private String name;
     private int id;
 
-
     /**
      * Represents a marker
      *
diff --git a/src/main/java/seng302/models/stream/XMLParser.java b/src/main/java/seng302/models/stream/XMLParser.java
index 53bb0889..19f9b9db 100644
--- a/src/main/java/seng302/models/stream/XMLParser.java
+++ b/src/main/java/seng302/models/stream/XMLParser.java
@@ -239,6 +239,9 @@ public class XMLParser {
         private ArrayList<Corner> compoundMarkSequence;
         private ArrayList<Limit> courseLimit;
 
+        // ensures there's no duplicate marks.
+        private List<Long> seenSourceIDs = new ArrayList<Long>();
+
         /**
          * Constructor for a RaceXMLObject.
          * Takes the information from a Document object and creates a more usable format.
@@ -312,6 +315,7 @@ public class XMLParser {
         private Map<Integer, Mark> createCompoundMarks(Element docEle) {
             Map<Integer, Mark> cMarks = new HashMap<>();
 
+
             NodeList cMarkList = docEle.getElementsByTagName("Course").item(0).getChildNodes();
             for (int i = 0; i < cMarkList.getLength(); i++) {
                 Node cMarkNode = cMarkList.item(i);
@@ -319,14 +323,15 @@ public class XMLParser {
                 if (cMarkNode.getNodeName().equals("CompoundMark")) {
                     Integer markID = getNodeAttributeInt(cMarkNode, "CompoundMarkID");
                     Mark mark = createMark(cMarkNode);
-
-                    cMarks.put(markID, mark);
+                    if (mark != null) {
+                        cMarks.put(markID, mark);
+                    }
                 }
             }
-
             return cMarks;
         }
 
+
         private Mark createMark(Node compoundMark) {
 
             List<SingleMark> marksList = new ArrayList<>();
@@ -348,6 +353,14 @@ public class XMLParser {
                 }
             }
 
+            for (SingleMark mark : marksList) {
+                if (seenSourceIDs.contains(mark.getId())) {
+                    return null;
+                } else {
+                    seenSourceIDs.add(mark.getId());
+                }
+            }
+
             if (marksList.size() == 1) {
                 return marksList.get(0);
             } else if (marksList.size() == 2) {