--- content_taxonomy_hs.module	2009-05-19 17:33:32.000000000 +0200
+++ content_taxonomy_hs_old.module	2009-05-19 17:30:08.000000000 +0200
@@ -290,7 +290,7 @@ function content_taxonomy_hs_widget($op,
           }
         }
         else {
-          $keys[$node_field['tids']] = $node_field['tids'];
+          $keys[(String) $node_field['tids']] = $node_field['tids'];
         }
         $node_field = content_transpose_array_rows_cols(array('value' => $keys));
         break;