diff --git a/ruby/lib/jam_ruby/models/music_session_user_history.rb b/ruby/lib/jam_ruby/models/music_session_user_history.rb
index 233c64774..94beb488d 100644
--- a/ruby/lib/jam_ruby/models/music_session_user_history.rb
+++ b/ruby/lib/jam_ruby/models/music_session_user_history.rb
@@ -17,6 +17,14 @@ module JamRuby
                :class_name => "MusicSessionHistory",
                :foreign_key => "music_session_id")
 
+    def self.latest_history(client_id)
+      self.where(:client_id => client_id)
+        .order('created_at DESC')
+        .limit(1)
+        .includes(:user)
+        .first
+    end
+
     def music_session_history
       @msh ||= JamRuby::MusicSessionHistory.find_by_music_session_id(self.music_session_id)
     end
@@ -104,10 +112,8 @@ module JamRuby
 
     def add_rating(rval, comment='')
       rval = rval.to_i
-      if 0 != rval 
-        self.rating = self.rating.to_i + rval
-        self.rating_comment = comment
-      end
+      self.rating = rval if 0 != rval 
+      self.rating_comment = comment
     end
 
     MIN_SESSION_DURATION_RATING = 60
@@ -118,5 +124,9 @@ module JamRuby
         Rails.env.development?
     end
 
+    def good_rating?
+      0 < self.rating.to_i
+    end
+
   end
 end
diff --git a/web/app/assets/javascripts/rateSessionDialog.js b/web/app/assets/javascripts/rateSessionDialog.js
index f9dc49e40..644585bb5 100644
--- a/web/app/assets/javascripts/rateSessionDialog.js
+++ b/web/app/assets/javascripts/rateSessionDialog.js
@@ -7,23 +7,25 @@
         var logger = context.JK.logger;
         var dialogId = 'rate-session-dialog';
         var $scopeSelector = "[layout-id='rate-session-dialog']";
+        var clientId = context.JK.JamServer.clientID;
 
         function reset() {
+            clientId = context.JK.JamServer.clientID;
             $('#btn-rate-session-up', $scopeSelector).removeClass('selected');
             $('#btn-rate-session-down', $scopeSelector).removeClass('selected');
             $('#txt-rate-session-comment',"[layout-id='rate-session-dialog']").val('');
         }
 
         function showDialog() {
-            if (context.JK.JamServer.clientID) {
+            if (clientId) {
+                reset();
                 $.ajax({
                     type: "GET",
-                    url: "/api/participant_histories/"+context.JK.JamServer.clientID
+                    url: "/api/participant_histories/"+clientId
                 }).done(function (response) {
                     if (response && 
                         response.hasOwnProperty('should_rate_session') && 
                         true==response['should_rate_session']) {
-                        reset();
                         app.layout.showDialog(dialogId);
                     }
                 });
@@ -81,7 +83,7 @@
                     closeDialog();
                     return false;
                 }
-                var url = "/api/participant_histories/"+context.JK.JamServer.clientID+"/rating";
+                var url = "/api/participant_histories/"+clientId+"/rating";
                 $.ajax({
                     type: "POST",
                     url: url,
diff --git a/web/app/controllers/api_music_sessions_controller.rb b/web/app/controllers/api_music_sessions_controller.rb
index adf807ac2..d832b68a0 100644
--- a/web/app/controllers/api_music_sessions_controller.rb
+++ b/web/app/controllers/api_music_sessions_controller.rb
@@ -151,7 +151,7 @@ class ApiMusicSessionsController < ApiController
   end
 
   def participant_rating
-    if @history = MusicSessionUserHistory.find_by_client_id(params[:client_id])
+    if @history = MusicSessionUserHistory.latest_history(params[:client_id])
       if request.post?
         @history.add_rating(params[:rating], params[:comment])
         @history.save
@@ -160,11 +160,10 @@ class ApiMusicSessionsController < ApiController
           response.status = :unprocessable_entity
           respond_with @history
         else
-          uu = @history.user
-          if (uu.first_good_music_session_at.nil?)
-            uu.first_good_music_session_at = Time.now
-            uu.save
-          end if uu
+          if @history.good_rating? && @history.user.first_good_music_session_at.nil?
+            @history.user.first_good_music_session_at = Time.now
+            @history.user.save
+          end
           render :json => {}, :status => :ok
         end
       elsif request.get?