Index: includes/entity.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/entity.inc,v
retrieving revision 1.16
diff -u -r1.16 entity.inc
--- includes/entity.inc	9 Oct 2010 02:36:46 -0000	1.16
+++ includes/entity.inc	19 Oct 2010 18:54:40 -0000
@@ -277,7 +277,7 @@
     }
     if ($conditions) {
       foreach ($conditions as $field => $value) {
-        $query->condition('base.' . $field, $value);
+        $query->condition('base.' . $field, $value, is_array($value) ? 'IN' : NULL);
       }
     }
     return $query;