diff --git a/includes/comment.inc b/includes/comment.inc
index 84d46ae..ed029b1 100644
--- a/includes/comment.inc
+++ b/includes/comment.inc
@@ -571,18 +571,66 @@ function project_issue_update_by_comment($comment_data, $op) {
   // Update the issue data to reflect the new final states.
   db_query("UPDATE {project_issues} SET pid = %d, category = '%s', component = '%s', priority = %d, rid = %d, assigned = %d, sid = %d, priority_weight = %d WHERE nid = %d", $comment_data->pid, $comment_data->category, $comment_data->component, $comment_data->priority, $comment_data->rid, $comment_data->assigned, $comment_data->sid, $priority_weight, $comment_data->nid);
 
-  // Update the issue title.
-  $node = node_load($comment_data->nid, NULL, TRUE);  // Don't use cached since we changed data above.
-  $node->title = $comment_data->title;
-
-  // This also updates the changed date of the issue.
-  node_save($node);
+  // Update the issue title, in case it changed.
+  // Don't use cached since we changed data above.
+  $node = node_load($comment_data->nid, NULL, TRUE);
+  if ($node->title !== $comment_data->title) {
+    // Node module's node_save() and _node_save_revision() would set the node
+    // revision author to the current user (the one who wrote an issue comment),
+    // change the node revision created/changed date as well as other node
+    // revision properties.
+    // However, for this node update, only the title of the issue node should be
+    // changed. All other properties of the existing node and node revision
+    // should remain unchanged, since the comment author did not edit the node,
+    // only wrote a comment.
+    // Therefore, we need to a custom implementation of node_save() that only
+    // updates the title, but still informs other modules about the change, and
+    // clears caches accordingly.
+    $node->title = $comment_data->title;
+    _project_issue_node_save($node);
+
+    // Clear the static node_load() cache.
+    node_load(NULL, NULL, TRUE);
+  }
 
   // Return the object of comment data we used to update the issue.
   return $comment_data;
 }
 
 /**
+ * Save a node object into the database.
+ *
+ * This node_save() replacement only works for existing nodes and updates the
+ * node title in {node} and {node_revision} only. Other properties remain
+ * unchanged.
+ *
+ * @see project_issue_update_by_comment()
+ * @see node_save()
+ */
+function _project_issue_node_save(&$node) {
+  // Let modules modify the node before it is saved to the database.
+  node_invoke_nodeapi($node, 'presave');
+
+  // Update {node}.title.
+  db_query("UPDATE {node} SET title = '%s' WHERE nid = %d", array($node->nid));
+
+  // Update {node_revision}.title.
+  db_query("UPDATE {node_revisions} SET title = '%s' WHERE vid = %d", array($node->vid));
+
+  $op = 'update';
+
+  // Call the node specific callback (if any).
+  node_invoke($node, $op);
+  node_invoke_nodeapi($node, $op);
+
+  // Update the node access table for this node.
+  node_access_acquire_grants($node);
+
+  // Clear the page and block caches.
+  cache_clear_all();
+}
+
+/**
  * Adjusts the filepath of issue followups so files are saved to
  * the correct issues directory.
  *