diff --git a/lib/model/doctrine/PluginDiaryComment.class.php b/lib/model/doctrine/PluginDiaryComment.class.php
index 63e9d81..f2ca925 100644
--- a/lib/model/doctrine/PluginDiaryComment.class.php
+++ b/lib/model/doctrine/PluginDiaryComment.class.php
@@ -29,8 +29,9 @@ abstract class PluginDiaryComment extends BaseDiaryComment
     if ($this->member_id !== $this->Diary->member_id)
     {
       Doctrine::getTable('DiaryCommentUnread')->register($this->Diary);
-      Doctrine::getTable('DiaryCommentUpdate')->update($this->Diary, $this->Member);
     }
+
+    Doctrine::getTable('DiaryCommentUpdate')->update($this->Diary, $this->Member);
   }
 
   public function isDeletable($memberId)
diff --git a/lib/model/doctrine/PluginDiaryCommentUpdateTable.class.php b/lib/model/doctrine/PluginDiaryCommentUpdateTable.class.php
index 9318035..74e2ab1 100644
--- a/lib/model/doctrine/PluginDiaryCommentUpdateTable.class.php
+++ b/lib/model/doctrine/PluginDiaryCommentUpdateTable.class.php
@@ -18,20 +18,23 @@ class PluginDiaryCommentUpdateTable extends Doctrine_Table
 {
   public function update(Diary $diary, Member $member)
   {
-    $object = $this->find(array($diary->id, $member->id));
+    $now = date('Y-m-d H:i:s');
 
-    if (!$object)
+    if ($diary->member_id !== $member->id)
     {
-      $object = new DiaryCommentUpdate();
-      $object->setDiary($diary);
-      $object->setMember($member);
-    }
+      $object = $this->find(array($diary->id, $member->id));
 
-    $now = date('Y-m-d H:i:s');
+      if (!$object)
+      {
+        $object = new DiaryCommentUpdate();
+        $object->setDiary($diary);
+        $object->setMember($member);
+      }
 
-    $object->setMyLastCommentTime($now);
-    $object->setLastCommentTime($now);
-    $object->save();
+      $object->setMyLastCommentTime($now);
+      $object->setLastCommentTime($now);
+      $object->save();
+    }
 
     $this->createQuery()->update()
       ->set('last_comment_time', '?', $now)