Index: modules/statistics/statistics.admin.inc
===================================================================
RCS file: /cvs/drupal/drupal/modules/statistics/statistics.admin.inc,v
retrieving revision 1.37
diff -u -p -r1.37 statistics.admin.inc
--- modules/statistics/statistics.admin.inc	20 Dec 2009 19:41:57 -0000	1.37
+++ modules/statistics/statistics.admin.inc	25 Jan 2010 15:32:38 -0000
@@ -118,8 +118,11 @@ function statistics_top_visitors() {
     ->limit(30)
     ->orderByHeader($header);
 
-  $count_query = db_select('accesslog');
-  $count_query->addExpression('COUNT(DISTINCT CONCAT(CAST(uid AS char), hostname))');
+  $uniques_query = db_select('accesslog')->distinct();
+  $uniques_query->addField('accesslog', 'uid', 'uid');
+  $uniques_query->addField('accesslog', 'hostname', 'hostname');
+  $count_query = db_select($uniques_query);
+  $count_query->addExpression('COUNT(*)');
   $query->setCountQuery($count_query);
 
   $result = $query->execute();