--- commentactivity.module	2008-01-21 22:47:31.000000000 +0800
+++ commentactivity.module	2008-03-06 15:47:24.000000000 +0800
@@ -86,6 +86,7 @@ function commentactivity_comment($a1, $o
     [nid] => 1 // the parent node id
     [uid] => 1 // the author id.
 */
+        $a1 = (array) $a1;
         $node = node_load($a1['nid']);
         $node_author = db_fetch_object(db_query('SELECT uid, name FROM {users} WHERE uid = %d', $node->uid));
         if ($a1['pid']) {