--- ezxhtmlxmloutput.php.orig	2008-12-11 11:11:32.000000000 +0100
+++ ezxhtmlxmloutput.php	2008-12-11 11:13:43.000000000 +0100
@@ -221,7 +221,11 @@
         elseif ( $element->getAttribute( 'node_id' ) != null )
         {
             $nodeID = $element->getAttribute( 'node_id' );
-            $node = $this->NodeArray[$nodeID];
+            $node = null;
+            if ( isset( $this->NodeArray[$nodeID] ) )
+            {
+                $node = $this->NodeArray[$nodeID];
+            }
 
             if ( $node != null )
             {