Index: node.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/node/node.module,v
retrieving revision 1.1013
diff -u -r1.1013 node.module
--- node.module	14 Jan 2009 21:16:20 -0000	1.1013
+++ node.module	16 Jan 2009 12:19:42 -0000
@@ -1136,7 +1136,12 @@
  *   An HTML representation of the themed node.
  */
 function node_view($node, $teaser = FALSE) {
-  $node = (object)$node;
+  if (is_object($node)) {
+    $node = drupal_clone($node);
+  }
+  else {
+    $node = (object)$node;
+  }
 
   $node = node_build_content($node, $teaser);