--- comment_driven.module
+++ comment_driven.module
@@ -540,3 +540,21 @@
   module_load_include('inc', 'comment_driven', 'comment_driven.admin');
   return _comment_driven_driven_global_settings_form();
 }
+
+/**
+ * Implements hook_nodeapi().
+ */
+function comment_driven_nodeapi(&$node, $op, $a3 = NULL, $a4  = NULL) {
+  switch ($op) {
+    case 'presave':
+      if (isset($node->associated_cid)) {
+        $node_before = node_load($node->nid);
+        $driven_props = driven_properties_available($node->type);
+        $changes = driven_inspect_diff_nodes($node_before, $node, $driven_props);
+        $diff_render = driven_diff_render($node->type, $changes);
+        $query = "INSERT INTO {comment_driven_log}(cid, old_vid, new_vid, changes, diff_render, timestamp) VALUES(%d, %d, %d, '%s', '%s', %d)";
+        db_query($query, $node->associated_cid, $node_before->vid, $node->vid, serialize($changes), serialize($diff_render), time());
+      }
+      break;
+  }
+}
\ No newline at end of file