diff --git a/src/org/ntlab/deltaViewer/CollaborationViewer.java b/src/org/ntlab/deltaViewer/CollaborationViewer.java
index 70a332e..9b9ef31 100644
--- a/src/org/ntlab/deltaViewer/CollaborationViewer.java
+++ b/src/org/ntlab/deltaViewer/CollaborationViewer.java
@@ -431,7 +431,7 @@
 				createMethodExecutionVertex(callerMethodExec.getThisObjId(), callerMethodExec.getSignature(), callerMethodExec);
 			}
 			createMethodExecutionVertex(objId, methodExecSignature, methodExec);
-		} else if (alias.getObjectId().matches("0") && !methodExecToVertexMap.containsKey(methodExec)) {
+		} else if (alias.getObjectId().startsWith("0:") && !methodExecToVertexMap.containsKey(methodExec)) {
 			createMethodExecutionVertex(objId, methodExecSignature, methodExec);
 		}		
 	}
diff --git a/src/org/ntlab/deltaViewer/DeltaViewer.java b/src/org/ntlab/deltaViewer/DeltaViewer.java
index 49b1f40..2294bb9 100644
--- a/src/org/ntlab/deltaViewer/DeltaViewer.java
+++ b/src/org/ntlab/deltaViewer/DeltaViewer.java
@@ -528,7 +528,7 @@
 				createMethodExecutionVertex(callerMethodExec.getThisObjId(), callerMethodExec.getSignature(), callerMethodExec);
 			}
 			createMethodExecutionVertex(objId, methodExecSignature, methodExec);
-		} else if (alias.getObjectId().matches("0") && !methodExecToVertexMap.containsKey(methodExec)) {
+		} else if (alias.getObjectId().startsWith("0:") && !methodExecToVertexMap.containsKey(methodExec)) {
 			createMethodExecutionVertex(objId, methodExecSignature, methodExec);
 		}
 	}
diff --git a/src/org/ntlab/deltaViewer/MagnetRONViewer.java b/src/org/ntlab/deltaViewer/MagnetRONViewer.java
index 62be2ee..e46c165 100644
--- a/src/org/ntlab/deltaViewer/MagnetRONViewer.java
+++ b/src/org/ntlab/deltaViewer/MagnetRONViewer.java
@@ -194,7 +194,7 @@
 				update();
 				break;
 			case THIS:
-				if (curFrame == 0 || alias.getObjectId().matches("0")) {
+				if (curFrame == 0 || alias.getObjectId().startsWith("0:")) {
 					createMethodExecutionVertex(alias);
 					update();
 				}
@@ -1328,7 +1328,7 @@
 		for (Entry<String, ObjectVertex> objectToVertexEntry: objectToVertexMap.entrySet()) {
 			String key = objectToVertexEntry.getKey();
 			ObjectVertex ov = objectToVertexEntry.getValue();
-			if (key.startsWith("0")) {
+			if (key.startsWith("0:")) {
 				staticObjectVertex.add(ov.getCell());
 			} else {
 				objectVertex.add(ov.getCell());