Index: node.module
===================================================================
--- node.module	(revision 164)
+++ node.module	(working copy)
@@ -997,7 +997,12 @@
  *   An HTML representation of the themed node.
  */
 function node_view($node, $teaser = FALSE, $page = FALSE, $links = TRUE) {
-  $node = (object)$node;
+  if (is_object($node)) {
+    $node = drupal_clone($node);
+  }
+  else {
+    $node = (object)$node;
+  }
 
   $node = node_build_content($node, $teaser, $page);