Index: themekey.node.inc
===================================================================
--- themekey.node.inc	(revision 2171)
+++ themekey.node.inc	(working copy)
@@ -25,8 +25,9 @@
 }
 
 function _themekey_node_callback(&$item, $parameters) {
-  $node = node_load($parameters['node:nid']);
-  if ($theme = _themekey_match_properties($parameters, $node)) {
-    $item['theme'] = $theme;
+  if ($node = node_load($parameters['node:nid'])) {
+    if ($theme = _themekey_match_properties($parameters, $node)) {
+      $item['theme'] = $theme;
+    }
   }
 }