Index: lams_tool_forum/src/java/org/lamsfoundation/lams/tool/forum/persistence/Message.java
===================================================================
diff -u -r0cae9f7a40ca2fd2c14a2d27f9c016cf7d708882 -r3fca8720f48328a4c5573b2d6d8f7dc89ad9fb45
--- lams_tool_forum/src/java/org/lamsfoundation/lams/tool/forum/persistence/Message.java	(.../Message.java)	(revision 0cae9f7a40ca2fd2c14a2d27f9c016cf7d708882)
+++ lams_tool_forum/src/java/org/lamsfoundation/lams/tool/forum/persistence/Message.java	(.../Message.java)	(revision 3fca8720f48328a4c5573b2d6d8f7dc89ad9fb45)
@@ -92,20 +92,21 @@
   		try{
   			msg = (Message) super.clone();
   			msg.setUid(null);
-  			if(parent != null){
-  				msg.parent = (Message) parent.clone();
-  				//try to keep parent uid, so avoid persistant a new instance in database for parent message 
-  				msg.parent.uid = parent.uid;
-  			}
-  			if(toolSession != null){
-  				msg.toolSession = (ForumToolSession) toolSession.clone();
-  			}
+  			//it is not necessary to deep clone following comment fields.
   			//don't  deep clone forum to avoid dead loop in clone
-  			if(createdBy != null){
-  				msg.createdBy = (ForumUser) createdBy.clone();
-  			}
-  			if(modifiedBy != null)
-  				msg.modifiedBy = (ForumUser) modifiedBy.clone();
+//  			if(parent != null){
+//  				msg.parent = (Message) parent.clone();
+//  				//try to keep parent uid, so avoid persistant a new instance in database for parent message 
+//  				msg.parent.uid = parent.uid;
+//  			}
+//  			if(toolSession != null){
+//  				msg.toolSession = (ForumToolSession) toolSession.clone();
+//  			}
+//  			if(createdBy != null){
+//  				msg.createdBy = (ForumUser) createdBy.clone();
+//  			}
+//  			if(modifiedBy != null)
+//  				msg.modifiedBy = (ForumUser) modifiedBy.clone();
   			//clone attachment
   			if(attachments != null){
   				Iterator iter = attachments.iterator();
Index: lams_tool_forum/src/java/org/lamsfoundation/lams/tool/forum/service/ForumService.java
===================================================================
diff -u -rb5d42eff472154edcc323444fb26d318a398481c -r3fca8720f48328a4c5573b2d6d8f7dc89ad9fb45
--- lams_tool_forum/src/java/org/lamsfoundation/lams/tool/forum/service/ForumService.java	(.../ForumService.java)	(revision b5d42eff472154edcc323444fb26d318a398481c)
+++ lams_tool_forum/src/java/org/lamsfoundation/lams/tool/forum/service/ForumService.java	(.../ForumService.java)	(revision 3fca8720f48328a4c5573b2d6d8f7dc89ad9fb45)
@@ -338,7 +338,6 @@
 			log.error("Failed on getting session by given sessionID:" + sessionId);
 			throw new ForumException("Failed on getting session by given sessionID:" + sessionId);
 		}
-		List topicsFromAuthor = messageDao.getTopicsFromAuthor(session.getForum().getUid());
 		
 		//sorted by last post date
 		Message msg;
@@ -348,11 +347,6 @@
 			msg = (Message) iter.next();
 			map.put(msg.getLastReplyDate(),msg);
 		}
-		iter = topicsFromAuthor.iterator();
-		while(iter.hasNext()){
-			msg = (Message) iter.next();
-			map.put(msg.getLastReplyDate(),msg);
-		}
 		return 	MessageDTO.getMessageDTO(new ArrayList<Message>(map.values()));
 		
 	}
@@ -695,6 +689,34 @@
 		Forum forum = forumDao.getByContentId(toolContentId);
 		session.setForum(forum);
 		forumToolSessionDao.saveOrUpdate(session);
+		
+		//also clone author created topic from this forum tool content!!!
+		//this can avoid topic record information conflict when multiple sessions are against same tool content
+		//for example, the reply number maybe various for different sessions.
+		List topicsFromAuthor = messageDao.getTopicsFromAuthor(session.getForum().getUid());
+		
+		//sorted by last post date
+		Message msg;
+		SortedMap<Date,Message> map = new TreeMap<Date,Message>(new DateComparator());
+		Iterator iter = topicsFromAuthor.iterator();
+		while(iter.hasNext()){
+			msg = (Message) iter.next();
+			//Don't copy other session's topic, only from tool content!!!.
+			if(msg.getToolSession() != null)
+				continue;
+			//set this message forum Uid as toContent
+			if(!msg.getIsAuthored())
+				continue;
+			Message newMsg = (Message) msg.clone();
+			//reset some value.
+			newMsg.setReplyNumber(0);
+			newMsg.setHideFlag(false);
+			//it should be new message
+			newMsg.setUid(null);
+			//!!! set current session to authored message
+			newMsg.setToolSession(session);
+			createRootTopic(toolContentId,null,newMsg);
+		}
 	}
 
 	public String leaveToolSession(Long toolSessionId, Long learnerId) throws DataMissingException, ToolException {