Fix bug.

app/models/bulletin.rb

@@ -107,6 +107,7 @@ class Bulletin
   before_create :set_expire
   before_save :check_limit
   before_save do
+    @is_hidden_changed = self.is_hidden_changed?
     if self.is_top_changed? && !self.is_top
       self.sort_number = nil
     end
@@ -431,6 +432,17 @@ class Bulletin
     related_feeds = BulletinFeed.any_of({:category_ids=>@category_id.to_s}, {:tag_ids.in=>@tag_ids.map(&:to_s)}).to_a
   end
   def notify_feed(type="create")
+    if @is_hidden_changed
+      if self.is_hidden
+        if type == 'create'
+          return []
+        else
+          type = 'destroy'
+        end
+      else
+        type = 'create'
+      end
+    end
     related_feeds = self.get_related_feeds.select{|feed| feed.remote_urls.count != 0}
     if related_feeds.count != 0
       bulletin_data = self.get_data