Index: relatedlinks.module
===================================================================
RCS file: /cvs/drupal/contributions/modules/relatedlinks/relatedlinks.module,v
retrieving revision 1.58.2.5
diff -u -p -r1.58.2.5 relatedlinks.module
--- relatedlinks.module	9 May 2008 06:23:59 -0000	1.58.2.5
+++ relatedlinks.module	11 Jun 2008 01:50:38 -0000
@@ -1130,7 +1130,18 @@ function _relatedlinks_collate_links($se
     $set = empty($set1) ? $set2 : $set1;
   }
   else {
-    $set = array_intersect_assoc($set1, $set2) + array_diff_assoc($set1, $set2);
+    /*
+    array_intersect_assoc() and array_diff_key() produce errors in PHP 5.2
+    due to the node objects not having a __toString() method.
+    array_intersect_key() and array_diff_key() are used if available - ie from
+    PHP 5.2 onwards.
+    */
+    if (function_exists('array_intersect_key')) {
+      $set = array_intersect_key($set1, $set2) + array_diff_key($set1, $set2);
+    }
+    else {
+      $set = array_intersect_assoc($set1, $set2) + array_diff_assoc($set1, $set2);
+    }
   }
 
   foreach ($set as $node) {