--- apachesolr.module.bak	2009-12-21 18:05:02.000000000 +0100
+++ apachesolr.module	2009-12-21 18:12:52.000000000 +0100
@@ -747,7 +747,7 @@
       foreach ($facets as $delta => $info) {
         $definitions[$module][$delta] = $info;
         if(isset($definitions[$module][$delta])) {
-          $definitions[$module][$delta]['operator'] = $operator_settings[$module][$delta];
+          $definitions[$module][$delta]['operator'] = isset($operator_settings[$module][$delta]) ? $operator_settings[$module][$delta] : 'AND';
         }
       }
     }