Index: /branches/release-35/lib/MT/App/Comments.pm
===================================================================
--- /branches/release-35/lib/MT/App/Comments.pm (revision 1873)
+++ /branches/release-35/lib/MT/App/Comments.pm (revision 1924)
@@ -924,5 +924,6 @@
     }
     if ($commenter) {
-        $commenter->url( $comment->url ) if $comment->url;
+        $commenter->url( $comment->url )
+          if $comment->url && $commenter->type != MT::Author::COMMENTER();
         $commenter->save
           or $app->log(