diff --git a/features/com.minres.scviewer.database.feature/pom.xml b/features/com.minres.scviewer.database.feature/pom.xml
index 3fc8ae0..ab564f8 100644
--- a/features/com.minres.scviewer.database.feature/pom.xml
+++ b/features/com.minres.scviewer.database.feature/pom.xml
@@ -8,5 +8,4 @@
   	<version>2.0.0-SNAPSHOT</version>
 	<relativePath>../..</relativePath>
   </parent>
-  <version>2.0.0-SNAPSHOT</version>
 </project>
diff --git a/plugins/com.minres.scviewer.database.sqlite/src/com/minres/scviewer/database/sqlite/TxStream.java b/plugins/com.minres.scviewer.database.sqlite/src/com/minres/scviewer/database/sqlite/TxStream.java
index 529bade..324825b 100644
--- a/plugins/com.minres.scviewer.database.sqlite/src/com/minres/scviewer/database/sqlite/TxStream.java
+++ b/plugins/com.minres.scviewer.database.sqlite/src/com/minres/scviewer/database/sqlite/TxStream.java
@@ -24,8 +24,8 @@ import com.minres.scviewer.database.EventKind;
 import com.minres.scviewer.database.HierNode;
 import com.minres.scviewer.database.IEvent;
 import com.minres.scviewer.database.IWaveform;
-import com.minres.scviewer.database.IWaveformDb;
 import com.minres.scviewer.database.RelationType;
+import com.minres.scviewer.database.RelationTypeFactory;
 import com.minres.scviewer.database.WaveformType;
 import com.minres.scviewer.database.sqlite.db.IDatabase;
 import com.minres.scviewer.database.sqlite.db.SQLiteDatabaseSelectHandler;
@@ -165,7 +165,7 @@ public class TxStream extends HierNode implements IWaveform {
 	}
 
 	public RelationType getRelationType(String name) {
-		RelationType relType=RelationType.create(name);
+		RelationType relType=RelationTypeFactory.create(name);
 		if(!usedRelationsList.contains(relType)) usedRelationsList.add(relType);
 		return relType;
 	}
diff --git a/plugins/com.minres.scviewer.database.ui.swt/src/com/minres/scviewer/database/ui/IWaveformView.java b/plugins/com.minres.scviewer.database.ui.swt/src/com/minres/scviewer/database/ui/IWaveformView.java
index 9830894..d166cc0 100644
--- a/plugins/com.minres.scviewer.database.ui.swt/src/com/minres/scviewer/database/ui/IWaveformView.java
+++ b/plugins/com.minres.scviewer.database.ui.swt/src/com/minres/scviewer/database/ui/IWaveformView.java
@@ -22,6 +22,7 @@ import org.eclipse.swt.widgets.Control;
 
 import com.minres.scviewer.database.IWaveform;
 import com.minres.scviewer.database.RelationType;
+import com.minres.scviewer.database.RelationTypeFactory;
 
 public interface IWaveformView extends PropertyChangeListener, ISelectionProvider{
 
@@ -29,7 +30,7 @@ public interface IWaveformView extends PropertyChangeListener, ISelectionProvide
 	
 	String MARKER_PROPERTY = "marker_time";
 	
-	public static final RelationType NEXT_PREV_IN_STREAM = RelationType.create("Prev/Next in stream"); 
+	public static final RelationType NEXT_PREV_IN_STREAM = RelationTypeFactory.create("Prev/Next in stream"); 
 
 	public void addSelectionChangedListener(ISelectionChangedListener listener);
 
diff --git a/plugins/com.minres.scviewer.database/pom.xml b/plugins/com.minres.scviewer.database/pom.xml
index 55ca613..f57e4cd 100644
--- a/plugins/com.minres.scviewer.database/pom.xml
+++ b/plugins/com.minres.scviewer.database/pom.xml
@@ -8,5 +8,4 @@
 	<relativePath>../..</relativePath>
   </parent>
   <packaging>eclipse-plugin</packaging>
-  <version>2.0.0-SNAPSHOT</version>
 </project>
diff --git a/plugins/com.minres.scviewer.database/src/com/minres/scviewer/database/RelationType.java b/plugins/com.minres.scviewer.database/src/com/minres/scviewer/database/RelationType.java
index d0b7727..16de19c 100644
--- a/plugins/com.minres.scviewer.database/src/com/minres/scviewer/database/RelationType.java
+++ b/plugins/com.minres.scviewer.database/src/com/minres/scviewer/database/RelationType.java
@@ -11,31 +11,16 @@
 package com.minres.scviewer.database;
 
 import java.io.Serializable;
-import java.util.HashMap;
 
 public class RelationType implements Serializable {
-	
 	/**
 	 * 
 	 */
 	private static final long serialVersionUID = 6394859077558971735L;
 
-	private static HashMap<String, RelationType> registry = new HashMap<>();
-	
 	private String name;
 
-	public static RelationType create(String name){
-		if(registry.containsKey(name)){
-			return registry.get(name);
-		}else{
-			RelationType relType = new RelationType(name);
-			registry.put(name, relType);
-			return relType;
-		}
-		
-	}
-	
-	private RelationType(String name) {
+	RelationType(String name) {
 		super();
 		this.name = name;
 	}
@@ -59,6 +44,9 @@ public class RelationType implements Serializable {
 	
 	@Override
 	public boolean equals(Object obj) {
-		return name.equals(obj);
+		if(obj instanceof RelationType)
+			return name.equals(((RelationType)obj).name);
+		else
+			return false;
 	}
 }
diff --git a/plugins/com.minres.scviewer.database/src/com/minres/scviewer/database/RelationTypeFactory.java b/plugins/com.minres.scviewer.database/src/com/minres/scviewer/database/RelationTypeFactory.java
new file mode 100644
index 0000000..582805b
--- /dev/null
+++ b/plugins/com.minres.scviewer.database/src/com/minres/scviewer/database/RelationTypeFactory.java
@@ -0,0 +1,22 @@
+package com.minres.scviewer.database;
+
+import java.util.HashMap;
+
+public class RelationTypeFactory {
+	
+	public static RelationType create(String name){
+		if(registry.containsKey(name)){
+			return registry.get(name);
+		}else{
+			RelationType relType = new RelationType(name);
+			registry.put(name, relType);
+			return relType;
+		}
+		
+	}
+
+	private RelationTypeFactory() {}
+	
+	private static HashMap<String, RelationType> registry = new HashMap<>();
+
+}
diff --git a/plugins/com.minres.scviewer.database/src/com/minres/scviewer/database/internal/WaveformDb.java b/plugins/com.minres.scviewer.database/src/com/minres/scviewer/database/internal/WaveformDb.java
index 3c509ab..32d20e8 100644
--- a/plugins/com.minres.scviewer.database/src/com/minres/scviewer/database/internal/WaveformDb.java
+++ b/plugins/com.minres.scviewer.database/src/com/minres/scviewer/database/internal/WaveformDb.java
@@ -11,7 +11,6 @@
 package com.minres.scviewer.database.internal;
 
 import java.io.File;
-import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
diff --git a/plugins/com.minres.scviewer.database/src/com/minres/scviewer/database/tx/ITxAttributeType.java b/plugins/com.minres.scviewer.database/src/com/minres/scviewer/database/tx/ITxAttributeType.java
index 355910b..fe21390 100644
--- a/plugins/com.minres.scviewer.database/src/com/minres/scviewer/database/tx/ITxAttributeType.java
+++ b/plugins/com.minres.scviewer.database/src/com/minres/scviewer/database/tx/ITxAttributeType.java
@@ -10,8 +10,6 @@
  *******************************************************************************/
 package com.minres.scviewer.database.tx;
 
-import java.io.Serializable;
-
 import com.minres.scviewer.database.AssociationType;
 import com.minres.scviewer.database.DataType;
 
diff --git a/plugins/com.minres.scviewer.e4.application/src/com/minres/scviewer/e4/application/elements/RelationTypeToolControl.java b/plugins/com.minres.scviewer.e4.application/src/com/minres/scviewer/e4/application/elements/RelationTypeToolControl.java
index bb38cb6..57b1914 100644
--- a/plugins/com.minres.scviewer.e4.application/src/com/minres/scviewer/e4/application/elements/RelationTypeToolControl.java
+++ b/plugins/com.minres.scviewer.e4.application/src/com/minres/scviewer/e4/application/elements/RelationTypeToolControl.java
@@ -30,6 +30,7 @@ import org.eclipse.swt.widgets.Combo;
 import org.eclipse.swt.widgets.Composite;
 
 import com.minres.scviewer.database.RelationType;
+import com.minres.scviewer.database.RelationTypeFactory;
 import com.minres.scviewer.database.tx.ITx;
 import com.minres.scviewer.e4.application.Messages;
 import com.minres.scviewer.e4.application.parts.PartListener;
@@ -50,7 +51,7 @@ public class RelationTypeToolControl extends PartListener implements ISelectionC
 	WaveformViewer waveformViewerPart;
 	
 	/** The dummy. */
-	RelationType dummy = RelationType.create(Messages.RelationTypeToolControl_0);
+	RelationType dummy = RelationTypeFactory.create(Messages.RelationTypeToolControl_0);
 	
 	/**
 	 * Instantiates a new relation type tool control.
diff --git a/plugins/com.minres.scviewer.e4.application/src/com/minres/scviewer/e4/application/parts/WaveformViewer.java b/plugins/com.minres.scviewer.e4.application/src/com/minres/scviewer/e4/application/parts/WaveformViewer.java
index 98bfa41..6d35d7c 100644
--- a/plugins/com.minres.scviewer.e4.application/src/com/minres/scviewer/e4/application/parts/WaveformViewer.java
+++ b/plugins/com.minres.scviewer.e4.application/src/com/minres/scviewer/e4/application/parts/WaveformViewer.java
@@ -87,6 +87,7 @@ import com.minres.scviewer.database.IWaveform;
 import com.minres.scviewer.database.IWaveformDb;
 import com.minres.scviewer.database.IWaveformDbFactory;
 import com.minres.scviewer.database.RelationType;
+import com.minres.scviewer.database.RelationTypeFactory;
 import com.minres.scviewer.database.tx.ITx;
 import com.minres.scviewer.database.tx.ITxAttribute;
 import com.minres.scviewer.database.tx.ITxEvent;
@@ -1237,7 +1238,7 @@ public class WaveformViewer implements IFileChangeListener, IPreferenceChangeLis
 	 * @param relationName the new navigation relation type
 	 */
 	public void setNavigationRelationType(String relationName) {
-		setNavigationRelationType(RelationType.create(relationName));
+		setNavigationRelationType(RelationTypeFactory.create(relationName));
 	}
 
 	/**