Index: token.module
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/token/token.module,v
retrieving revision 1.5.2.11
diff -u -r1.5.2.11 token.module
--- token.module	9 Jan 2008 23:00:10 -0000	1.5.2.11
+++ token.module	17 Jan 2008 04:49:08 -0000
@@ -218,7 +218,9 @@
 
   // Since objects in PHP5 are always passed by reference, we ensure we're
   // working on a copy of the object.
-  $object = drupal_clone($object);
+  if (is_object($object)) {
+    $object = drupal_clone($object);
+  }
 
   // Simple recursion check. This is to avoid content_view()'s potential
   // for endless looping when a filter uses tokens, which load the content