--- chatroom.js	2010-11-19 13:32:10.000000000 -0600
+++ chatroom_new.js	2010-11-19 15:13:23.000000000 -0600
@@ -10,7 +10,12 @@ $(document).ready(function () {
   Drupal.settings.chatroom.pageTitle = document.title;
   Drupal.settings.chatroom.hasFocus = true;
   if (Drupal.settings.chatroom.latestMsgId > 0) {
-    var targetOffset = $('div.new-message:last').offset().top;
+    //var targetOffset = $('div.new-message:last').offset().top;
+    var targetOffset = 0;
+    var lastNewMessage = $('div.new-message:last');
+    if (lastNewMessage && lastNewMessage.offset()) {
+        targetOffset = lastNewMessage.top;
+    }
     var boardOffset = $('#chatroom-board').offset().top;
     var scrollAmount = targetOffset - boardOffset;
     $('#chatroom-board').animate({scrollTop: '+='+ scrollAmount +'px'}, 500);