diff -urp comment_notify/comment_notify.inc comment_notify_new/comment_notify.inc
--- comment_notify/comment_notify.inc	2011-11-03 02:45:28.000000000 +1000
+++ comment_notify_new/comment_notify.inc	2012-03-09 09:42:17.000000000 +1000
@@ -259,11 +259,25 @@ function comment_notify_unsubscribe_by_e
  * @return boolean
  */
 function comment_notify_unsubscribe_by_hash($hash) {
+  //get all this user's comments for this node
+  $result = db_query("SELECT c.cid
+    FROM {comment} c, (
+      SELECT oc.nid, oc.uid
+      FROM {comment} AS oc, comment_notify AS ocn
+      WHERE oc.cid = ocn.cid
+      AND ocn.notify_hash = :hash
+    ) AS o
+    WHERE o.nid = c.nid
+    AND o.uid = c.uid", array(':hash' => $hash));
+
+  $cids = $result->fetchCol();
+
+  //update all comment notifications to be disabled
   return (bool)db_update('comment_notify')
     ->fields(array(
       'notify' => 0,
     ))
-    ->condition('notify_hash', $hash)
+    ->condition('cid', $cids, 'IN')
     ->execute();
 }