diff --git a/src/org/aavso/tools/vstar/ui/mediator/DocumentManager.java b/src/org/aavso/tools/vstar/ui/mediator/DocumentManager.java
index 486fce70..56c9d51f 100644
--- a/src/org/aavso/tools/vstar/ui/mediator/DocumentManager.java
+++ b/src/org/aavso/tools/vstar/ui/mediator/DocumentManager.java
@@ -73,42 +73,7 @@ public class DocumentManager {
 	public DocumentManager() {
 	    mediator = Mediator.getInstance();
 
-		rawDataModelComponents = new HashMap<String, SyntheticObservationListPane<AbstractModelObservationTableModel>>();
-		phasedModelComponents = new HashMap<String, SyntheticObservationListPane<AbstractModelObservationTableModel>>();
-
-		rawDataResidualComponents = new HashMap<String, SyntheticObservationListPane<AbstractModelObservationTableModel>>();
-		phasedResidualComponents = new HashMap<String, SyntheticObservationListPane<AbstractModelObservationTableModel>>();
-
-		phasePlotExists = false;
-		epoch = 0;
-		period = 0;
-
-		showErrorBars = new HashMap<AnalysisType, Boolean>() {{
-		    put(AnalysisType.RAW_DATA, true);
-            put(AnalysisType.PHASE_PLOT, true);
-		}};
-		
-		showCrossHairs = new HashMap<AnalysisType, Boolean>() {{
-            put(AnalysisType.RAW_DATA, true);
-            put(AnalysisType.PHASE_PLOT, true);
-        }};
-        
-        invertRange = new HashMap<AnalysisType, Boolean>() {{
-            put(AnalysisType.RAW_DATA, true);
-            put(AnalysisType.PHASE_PLOT, true);
-        }};
-        
-        invertSeriesOrder = new HashMap<AnalysisType, Boolean>() {{
-            put(AnalysisType.RAW_DATA, true);
-            put(AnalysisType.PHASE_PLOT, true);
-        }};
-        
-        joinMeans = new HashMap<AnalysisType, Boolean>() {{
-            put(AnalysisType.RAW_DATA, true);
-            put(AnalysisType.PHASE_PLOT, true);
-        }};
-        
-		statsInfo = new TreeMap<String, String>();
+		init();
 	}
 
 	// ** phase, epoch, period methods **
@@ -348,6 +313,73 @@ private String getPhasedModelKey(IModel model) {
 				period);
 	}
 
+	/**
+	 * Initialise (or reset) data members
+	 */
+	public void init() {
+        phasePlotExists = false;
+        epoch = 0;
+        period = 0;
+
+	    // model maps
+	    if (rawDataModelComponents == null) {
+	        rawDataModelComponents = new HashMap<String, SyntheticObservationListPane<AbstractModelObservationTableModel>>();
+	    }
+	    rawDataModelComponents.clear();
+
+        if (phasedModelComponents == null) {
+            phasedModelComponents = new HashMap<String, SyntheticObservationListPane<AbstractModelObservationTableModel>>();
+        }
+        phasedModelComponents.clear();
+
+        if (rawDataResidualComponents == null) {
+            rawDataResidualComponents = new HashMap<String, SyntheticObservationListPane<AbstractModelObservationTableModel>>();
+        }
+        rawDataResidualComponents.clear();
+
+        if (phasedResidualComponents == null) {
+            phasedResidualComponents = new HashMap<String, SyntheticObservationListPane<AbstractModelObservationTableModel>>();
+        }
+        phasedResidualComponents.clear();
+
+	    // Boolean maps
+	    if (showErrorBars == null) {
+            showErrorBars = new HashMap<AnalysisType, Boolean>();
+	    }
+	    showErrorBars.put(AnalysisType.RAW_DATA, true);
+	    showErrorBars.put(AnalysisType.PHASE_PLOT, true);
+
+        if (showCrossHairs == null) {
+            showCrossHairs = new HashMap<AnalysisType, Boolean>();
+        }
+        showCrossHairs.put(AnalysisType.RAW_DATA, true);
+        showCrossHairs.put(AnalysisType.PHASE_PLOT, true);
+
+        if (invertRange == null) {
+            invertRange = new HashMap<AnalysisType, Boolean>();
+        }
+        invertRange.put(AnalysisType.RAW_DATA, true);
+        invertRange.put(AnalysisType.PHASE_PLOT, true);
+
+        if (invertSeriesOrder == null) {
+            invertSeriesOrder = new HashMap<AnalysisType, Boolean>();
+        }
+        invertSeriesOrder.put(AnalysisType.RAW_DATA, true);
+        invertSeriesOrder.put(AnalysisType.PHASE_PLOT, true);
+
+        if (joinMeans == null) {
+            joinMeans = new HashMap<AnalysisType, Boolean>();
+        }
+        joinMeans.put(AnalysisType.RAW_DATA, true);
+        joinMeans.put(AnalysisType.PHASE_PLOT, true);
+
+        // stats info map
+        if (statsInfo == null) {
+            statsInfo = new TreeMap<String, String>();
+        }
+        statsInfo.clear();
+	}
+
 	/**
 	 * Return a phase change listener that updates epoch and period information
 	 * in preparation for creating or retrieving phase plot components.<br/>
@@ -371,26 +403,6 @@ public boolean canBeRemoved() {
 		};
 	}
 
-	/**
-	 * Return a new star listener that clears the maps.
-	 */
-	public Listener<NewStarMessage> createNewStarListener() {
-		return new Listener<NewStarMessage>() {
-			@Override
-			public void update(NewStarMessage info) {
-				rawDataModelComponents.clear();
-				rawDataResidualComponents.clear();
-				phasedModelComponents.clear();
-				phasedResidualComponents.clear();
-			}
-
-			@Override
-			public boolean canBeRemoved() {
-				return false;
-			}
-		};
-	}
-
 	/**
 	 * Find and return the active window or null if one does not exist, e.g. the
 	 * case where the UI is that of an applet.
diff --git a/src/org/aavso/tools/vstar/ui/mediator/Mediator.java b/src/org/aavso/tools/vstar/ui/mediator/Mediator.java
index a3510e1a..5fa90c09 100644
--- a/src/org/aavso/tools/vstar/ui/mediator/Mediator.java
+++ b/src/org/aavso/tools/vstar/ui/mediator/Mediator.java
@@ -956,7 +956,6 @@ public DocumentManager getDocumentManager() {
 		if (documentManager == null) {
 			documentManager = new DocumentManager();
 			phaseChangeNotifier.addListener(documentManager.createPhaseChangeListener(), true);
-			newStarNotifier.addListener(documentManager.createNewStarListener(), true);
 		}
 
 		return documentManager;
@@ -1174,7 +1173,7 @@ public void createNewStarObservationArtefacts(NewStarType newStarType, StarInfo
 		// table and plot models, along with corresponding GUI components.
 
 		// Handle additive load if requested and observations are already
-		// loaded.
+		// loaded, otherwise, initialise the document manager.
 		if (addObs && getLatestNewStarMessage() != null) {
 			// convertObsToHJD(starInfo);
 
@@ -1192,6 +1191,8 @@ public void createNewStarObservationArtefacts(NewStarType newStarType, StarInfo
 					break;
 				}
 			}
+		} else {
+		    getDocumentManager().init();
 		}
 
 		List<ValidObservation> validObsList = starInfo.getRetriever().getValidObservations();