diff --git a/app/models/course_activity.rb b/app/models/course_activity.rb
index 103796a72..4e74142ad 100644
--- a/app/models/course_activity.rb
+++ b/app/models/course_activity.rb
@@ -14,13 +14,19 @@ class CourseActivity < ActiveRecord::Base
     if user_activity
       user_activity.save
     else
-      user_activity = UserActivity.new
-      user_activity.act_id = self.course_act_id
-      user_activity.act_type = self.course_act_type
-      user_activity.container_type = "Course"
-      user_activity.container_id = self.course_id
-      user_activity.user_id = self.user_id
-      user_activity.save
+      if self.course_act_type == 'Message' && !self.course_act.parent_id.nil?
+        user_activity = UserActivity.where("act_type = 'Message' and act_id = #{self.course_act.parent.id}").first
+        user_activity.created_at = self.created_at
+        user_activity.save
+      else
+        user_activity = UserActivity.new
+        user_activity.act_id = self.course_act_id
+        user_activity.act_type = self.course_act_type
+        user_activity.container_type = "Course"
+        user_activity.container_id = self.course_id
+        user_activity.user_id = self.user_id
+        user_activity.save
+      end
     end
   end
 
diff --git a/app/models/forge_activity.rb b/app/models/forge_activity.rb
index 9bc10bebf..c4f13c6d0 100644
--- a/app/models/forge_activity.rb
+++ b/app/models/forge_activity.rb
@@ -29,12 +29,19 @@ class ForgeActivity < ActiveRecord::Base
     if user_activity
       user_activity.save
     else
-      user_activity = UserActivity.new
-      user_activity.act_id = self.forge_act_id
-      user_activity.act_type = self.forge_act_type
-      user_activity.container_type = "Project"
-      user_activity.container_id = self.project_id
-      user_activity.save
+      if self.forge_act_type == 'Message' && !self.forge_act.parent_id.nil?
+        user_activity = UserActivity.where("act_type = 'Message' and act_id = #{self.forge_act.parent.id}").first
+        user_activity.created_at = self.created_at
+        user_activity.save
+      else
+        user_activity = UserActivity.new
+        user_activity.act_id = self.forge_act_id
+        user_activity.act_type = self.forge_act_type
+        user_activity.container_type = "Project"
+        user_activity.container_id = self.project_id
+        user_activity.user_id = self.user_id
+        user_activity.save
+      end
     end
   end
 
diff --git a/db/schema.rb b/db/schema.rb
index 008e13129..9f81c43cf 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -11,7 +11,7 @@
 #
 # It's strongly recommended to check this file into your version control system.
 
-ActiveRecord::Schema.define(:version => 20150911031029) do
+ActiveRecord::Schema.define(:version => 20150911064528) do
 
   create_table "activities", :force => true do |t|
     t.integer  "act_id",                                  :null => false
@@ -476,13 +476,6 @@ ActiveRecord::Schema.define(:version => 20150911031029) do
 
   add_index "delayed_jobs", ["priority", "run_at"], :name => "delayed_jobs_priority"
 
-  create_table "discuss_demos", :force => true do |t|
-    t.string   "title"
-    t.text     "body"
-    t.datetime "created_at", :null => false
-    t.datetime "updated_at", :null => false
-  end
-
   create_table "documents", :force => true do |t|
     t.integer  "project_id",                :default => 0,  :null => false
     t.integer  "category_id",               :default => 0,  :null => false
@@ -497,26 +490,23 @@ ActiveRecord::Schema.define(:version => 20150911031029) do
   add_index "documents", ["created_on"], :name => "index_documents_on_created_on"
   add_index "documents", ["project_id"], :name => "documents_project_id"
 
-  create_table "dts", :primary_key => "Num", :force => true do |t|
-    t.string   "Defect",        :limit => 50
-    t.string   "Category",      :limit => 50
-    t.string   "File"
-    t.string   "Method"
-    t.string   "Module",        :limit => 20
-    t.string   "Variable",      :limit => 50
-    t.integer  "StartLine"
-    t.integer  "IPLine"
-    t.string   "IPLineCode",    :limit => 200
-    t.string   "Judge",         :limit => 15
-    t.integer  "Review",        :limit => 1
+  create_table "dts", :force => true do |t|
+    t.string   "IPLineCode"
     t.string   "Description"
-    t.text     "PreConditions", :limit => 2147483647
-    t.text     "TraceInfo",     :limit => 2147483647
-    t.text     "Code",          :limit => 2147483647
+    t.string   "Num"
+    t.string   "Variable"
+    t.string   "TraceInfo"
+    t.string   "Method"
+    t.string   "File"
+    t.string   "IPLine"
+    t.string   "Review"
+    t.string   "Category"
+    t.string   "Defect"
+    t.string   "PreConditions"
+    t.string   "StartLine"
     t.integer  "project_id"
-    t.datetime "created_at"
-    t.datetime "updated_at"
-    t.integer  "id",                                  :null => false
+    t.datetime "created_at",    :null => false
+    t.datetime "updated_at",    :null => false
   end
 
   create_table "enabled_modules", :force => true do |t|
@@ -916,6 +906,7 @@ ActiveRecord::Schema.define(:version => 20150911031029) do
     t.datetime "created_on"
     t.integer  "comments_count",               :default => 0,  :null => false
     t.integer  "course_id"
+    t.datetime "updated_on"
   end
 
   add_index "news", ["author_id"], :name => "index_news_on_author_id"