--- webform.submissions.inc	2011-05-04 15:46:19.608260949 +0530
+++ webform.submissions_patch.inc	2011-05-04 15:51:09.028261806 +0530
@@ -706,7 +706,9 @@
     }
     if ($uid === 0) {
       $submissions = isset($_SESSION['webform_submission']) ? $_SESSION['webform_submission'] : array();
-	  $query->condition('sid', $submissions, 'IN');
+	  if (count($submissions) > 0) {
+	  	$query->condition('sid', $submissions, 'IN');
+	  }
     }
 
     $counts[$nid][$uid] = $query->countQuery()->execute()->fetchField();