? comment_timestamp.patch
Index: modules/comment/comment.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/comment/comment.module,v
retrieving revision 1.630
diff -u -p -r1.630 comment.module
--- modules/comment/comment.module	25 Apr 2008 18:34:05 -0000	1.630
+++ modules/comment/comment.module	1 May 2008 22:36:28 -0000
@@ -741,7 +741,9 @@ function comment_save($edit) {
           }
         }
 
-        $edit['timestamp'] = time();
+        if (empty($edit['timestamp'])) {
+          $edit['timestamp'] = time();
+        }
 
         if ($edit['uid'] === $user->uid) { // '===' because we want to modify anonymous users too
           $edit['name'] = $user->name;