diff --git a/src/org/ntlab/traceDebugger/CallStackModel.java b/src/org/ntlab/traceDebugger/CallStackModel.java
index 147e272..5fbc854 100644
--- a/src/org/ntlab/traceDebugger/CallStackModel.java
+++ b/src/org/ntlab/traceDebugger/CallStackModel.java
@@ -38,7 +38,13 @@
 		String declaringType = Trace.getDeclaringType(signature, isConstructor);
 		declaringType = declaringType.substring(declaringType.lastIndexOf(".") + 1);
 		String methodName = Trace.getMethodName(signature);
-		String args = "(" + signature.split("\\(")[1];
+		String args = "(";
+		String delimiter = "";
+		String[] argArray = signature.split("\\(")[1].split(",");
+		for (String arg : argArray) {
+			args += (delimiter + arg.substring(arg.lastIndexOf(".") + 1));
+			delimiter = ", ";
+		}
 		
 		StringBuilder sb = new StringBuilder();
 		sb.append(objectType);
diff --git a/src/org/ntlab/traceDebugger/CallTreeModel.java b/src/org/ntlab/traceDebugger/CallTreeModel.java
index ee2a1ff..21278d3 100644
--- a/src/org/ntlab/traceDebugger/CallTreeModel.java
+++ b/src/org/ntlab/traceDebugger/CallTreeModel.java
@@ -33,7 +33,13 @@
 		String declaringType = Trace.getDeclaringType(signature, isConstructor);
 		declaringType = declaringType.substring(declaringType.lastIndexOf(".") + 1);
 		String methodName = Trace.getMethodName(signature);
-		String args = "(" + signature.split("\\(")[1];
+		String args = "(";
+		String delimiter = "";
+		String[] argArray = signature.split("\\(")[1].split(",");
+		for (String arg : argArray) {
+			args += (delimiter + arg.substring(arg.lastIndexOf(".") + 1));
+			delimiter = ", ";
+		}
 		
 		StringBuilder sb = new StringBuilder();
 		sb.append(objectType);
diff --git a/src/org/ntlab/traceDebugger/CallTreeModels.java b/src/org/ntlab/traceDebugger/CallTreeModels.java
index e9ba525..248a8f9 100644
--- a/src/org/ntlab/traceDebugger/CallTreeModels.java
+++ b/src/org/ntlab/traceDebugger/CallTreeModels.java
@@ -66,21 +66,25 @@
 		MethodExecution coordinatorME = deltaMarkerManager.getMethodExecution(coordinatorMarker);
 		CallTreeModel coordinator = new CallTreeModel(coordinatorME);
 		callTreeModelsMemo.put(coordinatorME, coordinator);
-		for (IMarker srcSideMarker : srcSideMarkers) {
-			MethodExecution me = deltaMarkerManager.getMethodExecution(srcSideMarker);
-			CallTreeModel callTreeModel = new CallTreeModel(me);
-			if (!(callTreeModelsMemo.containsKey(me))) {
-				callTreeModelsMemo.put(me, callTreeModel);
-				create(callTreeModel, coordinatorME);
+		if (srcSideMarkers != null) {
+			for (IMarker srcSideMarker : srcSideMarkers) {
+				MethodExecution me = deltaMarkerManager.getMethodExecution(srcSideMarker);
+				CallTreeModel callTreeModel = new CallTreeModel(me);
+				if (!(callTreeModelsMemo.containsKey(me))) {
+					callTreeModelsMemo.put(me, callTreeModel);
+					create(callTreeModel, coordinatorME);
+				}
 			}
 		}
-		for (IMarker dstSideMarker : dstSideMarkers) {
-			MethodExecution me = deltaMarkerManager.getMethodExecution(dstSideMarker);
-			CallTreeModel callTreeModel = new CallTreeModel(me);
-			if (!(callTreeModelsMemo.containsKey(me))) {
-				callTreeModelsMemo.put(me, callTreeModel);
-				create(callTreeModel, coordinatorME);
-			}
+		if (dstSideMarkers != null) {
+			for (IMarker dstSideMarker : dstSideMarkers) {
+				MethodExecution me = deltaMarkerManager.getMethodExecution(dstSideMarker);
+				CallTreeModel callTreeModel = new CallTreeModel(me);
+				if (!(callTreeModelsMemo.containsKey(me))) {
+					callTreeModelsMemo.put(me, callTreeModel);
+					create(callTreeModel, coordinatorME);
+				}
+			}	
 		}
 		MethodExecution bottomME = deltaMarkerManager.getMethodExecution(bottomMarker);
 		CallTreeModel bottom = new CallTreeModel(bottomME);
diff --git a/src/org/ntlab/traceDebugger/VariableView.java b/src/org/ntlab/traceDebugger/VariableView.java
index ab4bda0..d398d22 100644
--- a/src/org/ntlab/traceDebugger/VariableView.java
+++ b/src/org/ntlab/traceDebugger/VariableView.java
@@ -222,8 +222,12 @@
 		List<IMarker> srcSideDeltaMarkers = markers.get(DeltaMarkerManager.SRC_SIDE_DELTA_MARKER);
 		List<IMarker> dstSideDeltaMarkers = markers.get(DeltaMarkerManager.DST_SIDE_DELTA_MARKER);
 		List<IMarker> coordinatorMarker = markers.get(DeltaMarkerManager.COORDINATOR_DELTA_MARKER);
-		markVariables(DeltaMarkerManager.SRC_SIDE_DELTA_MARKER, srcSideDeltaMarkers);
-		markVariables(DeltaMarkerManager.DST_SIDE_DELTA_MARKER, dstSideDeltaMarkers);
+		if (srcSideDeltaMarkers != null) {
+			markVariables(DeltaMarkerManager.SRC_SIDE_DELTA_MARKER, srcSideDeltaMarkers);	
+		}
+		if (dstSideDeltaMarkers != null) {
+			markVariables(DeltaMarkerManager.DST_SIDE_DELTA_MARKER, dstSideDeltaMarkers);	
+		}
 		markVariables(DeltaMarkerManager.COORDINATOR_DELTA_MARKER, coordinatorMarker);
 		viewer.refresh();
 		expandAllMarkedNodes();
diff --git a/src/org/ntlab/traceDebugger/analyzerProvider/DeltaExtractionAnalyzer.java b/src/org/ntlab/traceDebugger/analyzerProvider/DeltaExtractionAnalyzer.java
index 13e9877..8a951d2 100644
--- a/src/org/ntlab/traceDebugger/analyzerProvider/DeltaExtractionAnalyzer.java
+++ b/src/org/ntlab/traceDebugger/analyzerProvider/DeltaExtractionAnalyzer.java
@@ -59,13 +59,23 @@
 		MethodExecution me = bottomPoint.getMethodExecution();
 		MethodExecution childMe = null;
 		while (me != null) {
-			childMe = me;
-			me = me.getParent();
 			if (coordinator.equals(me)) {
-				TracePoint coordinatorPoint = childMe.getCallerTracePoint();
+				TracePoint coordinatorPoint;
+				if (childMe != null) {
+					coordinatorPoint = childMe.getCallerTracePoint();
+				} else {
+					coordinatorPoint = bottomPoint;
+				}
 				deltaMarkerView.setCoordinatorPoint(coordinatorPoint);		
 				break;
 			}
+			childMe = me;
+			me = me.getParent();
+//			if (coordinator.equals(me)) {
+//				TracePoint coordinatorPoint = childMe.getCallerTracePoint();
+//				deltaMarkerView.setCoordinatorPoint(coordinatorPoint);		
+//				break;
+//			}
 		}
 
 		// �f���^���o�̌��ʂ����Ƀ\�[�X�R�[�h�𔽓]�\������
diff --git a/src/org/ntlab/traceDebugger/analyzerProvider/DeltaMarkerManager.java b/src/org/ntlab/traceDebugger/analyzerProvider/DeltaMarkerManager.java
index 9a499e9..7b7d6b5 100644
--- a/src/org/ntlab/traceDebugger/analyzerProvider/DeltaMarkerManager.java
+++ b/src/org/ntlab/traceDebugger/analyzerProvider/DeltaMarkerManager.java
@@ -415,10 +415,17 @@
 							name2 = name2.substring(0, name2.indexOf("(") + 1);
 							name2 = name2.substring(name2.lastIndexOf(".") + 1);
 							if (!(name1.equals(name2))) return true;
-							String receiverName = node.getExpression().toString();
+//							String receiverName = node.getExpression().toString();
+							Expression expression = node.getExpression();
+							String receiverName = "";
+							if (expression != null) {
+								receiverName = expression.toString();
+							}
 							int start = node.getStartPosition();
 							if (source.startsWith("this.", start)) {
 								start += ("this." + receiverName + ".").length();
+							} else if (source.startsWith("super.", start)) {
+								start += ("super." + receiverName + ".").length();
 							} else {
 								start += (receiverName + ".").length();
 							}