--- og_forum.module	2009-07-20 12:16:57.000000000 +1000
+++ og_forum_hidden.module	2009-07-20 14:29:12.000000000 +1000
@@ -1675,13 +1675,13 @@ function og_forum_format($topic) {
   }
 }
 
-function og_forum_preprocess_node($variables) {
+function og_forum_preprocess_node(&$variables) {
   if ($variables['type'] == 'forum') {
     _og_forum_set_breadcrumb($variables['tid'], TRUE); 
   }
 }
 
-function og_forum_preprocess_forums($variables) {
+function og_forum_preprocess_forums(&$variables) {
   if (!empty($variables['forums'])) {
       $forums = og_forum_get_forums($variables['tid']);
       $variables['forums'] = theme('forum_list', $forums, $variables['parents'], $variables['tid']);